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Comparative anatomy and systematics of twelve woody Australasian genera of the Saxifragaceae

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Title:
Comparative anatomy and systematics of twelve woody Australasian genera of the Saxifragaceae
Creator:
Hils, Matthew Henry, 1955- ( Dissertant )
Lucansky, Terry W. ( Thesis advisor )
Herl, Robert J. ( Reviewer )
Huffman, Jacob B. ( Reviewer )
Judd, Walter S. ( Reviewer )
Stern, William Louis ( Reviewer )
Place of Publication:
Gainesville, Fla.
Publisher:
University of Florida
Publication Date:
Copyright Date:
1985
Language:
English

Subjects

Subjects / Keywords:
Anatomy ( jstor )
Cells ( jstor )
Epidermis ( jstor )
Genera ( jstor )
Leaves ( jstor )
Parenchyma ( jstor )
Petioles ( jstor )
Secondary xylem ( jstor )
Species ( jstor )
Tracheids ( jstor )
Botany thesis Ph. D.
Dissertations, Academic -- Botany -- UF
Saxifragaceae
Woody plants
Genre:
bibliography ( marcgt )
non-fiction ( marcgt )

Notes

Abstract:
Vegetative anatomical data are provided for twelve woody saxifragaceous genera from Australasia. These data are used, where possible, to determine the taxonomic position of these plants. The twelve genera are Tetracarpaea, Ixerba, Bauera, Anopterus, Cuttsia, Abrophyllum, Carpodetus, Argophyllum, Corokia, Donatia, Anodopetalum and Aphanopetalum. Typically these taxa possess dorsiventral leaves with uniseriate epidermides and anomocytic stomatal apparatuses. The nodal pattern is either unilacunar, one-trace or trilacunar, three-trace. The wood possesses angular, solitary pores, long vessel elements with oblique, scalariform perforation plates, tracheids with spiral thickenings and sparse axial parenchyma. Cuttsia, Abrophyllum, Carpodetus, Ixerba, Anopterus, Corokia and Argophyllum possess most or all of eleven anatomical features of an archetypical woody saxifrage. While wood anatomy is similar among Tetracarpaea, Bauera and an archetypical woody saxifrage, leaf anatomy is distinctive for each group. Donatia, Anodopetalum and Aphanopetalum possess few anatomical features of an archetypical woody saxifrage. Ixerba is anatomically isolated from the Brexioideae, but is similar to Anopterus in the Escallonioideae. Cuttsia and Abrophyllum are very similar anatomically and closely related. Anatomical data do not support the maintenance of the tribe Argophylleae of the Escallonioideae which includes Carpodetus, Corokia and Argo- phyllum. Carpodetus is more similar anatomically to Cuttsia and Abrophyllum than to Corokia and Argophyllum. Corokia and Argophyllum are very similar anatomically and probably closely related, but their taxonomic position remains obscure. Anatomical data support the union of the genus Argyrocalymma with Carpodetus, and the union of the genus Colmeiroa with Corokia. Tetracarpaea and Bauera are anatomically distinctive and isolated genera and may deserve familial status. Tetracarpaea is more closely allied to the Saxifragaceae based upon its wood anatomy, while Bauera is more closely allied to the Cunoniaceae because of its oppo- site leaves and foliaceous stipules. The nodal, leaf and wood anatomy of Anodopetalum is more similar to that of the Cunoniaceae than to that of the Saxifragaceae. Aphano- petalum and Donatia are readily distinguishable and isolated from the Saxifragaceae, but their taxonomic positions remain obscure. Donatia should probably be placed in its own family, but Aphanopetalum remains an enigma.
Thesis:
Thesis (Ph.D.)--University of Florida 1985.
Bibliography:
Includes bibliographical references (leaves 229-239).
General Note:
Vita.
General Note:
Typescript.
Statement of Responsibility:
by Matthew Henry Hils

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COMPARATIVE ANATOMY AND SYSTEMATICS OF
TWELVE WOODY AUSTRALASIAN GENERA
OF THE SAXIFRAGACEAE








By

MATTHEW HENRY HILS


A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF' FLORIDA IN
PARTIAL FULFILLMENT OF THE REQUIREMENTS
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY



UNIVERSITY OF FLORIDA


1985













ACKNOWLEDGEMENTS

I thank the members of my committee, Drs. Lucansky, Feri, Huffman, Judd and Stern for their guidance and patience in helping me complete this dissertation. I am especially grateful to Dr. Lucansky for his extensive help in organizing and criticizing this dissertation, and Dr. Stern for posing the research problem and providing the samples and materials with which to work. Special thanks go to Dr. Nordlie for his eleventh hour efforts. My thanks also go to the rest of the faculty and graduate students of

the Department of Botany for the many questions they answered and their encouragement. I express gratitude to my colleagues, friends and students at Hiram College who have been very supportive during the past year. Robert Sawyer and Robert Kiger provided help with translation of a Latin

description, and Wes Tree assisted with the photographs.I am very grateful to John W. Thieret, friend and colleague, for his counsel and assistance over the past six years. I

also am very fortunate to have the full support of my family in my work; I owe them more than I could ever repay. Lastly, I dedicate this work to my wife, Wendy E. Mahon-Hils, who has provided the illustrations within, but more importantly, has given me more love and understanding than I could ever hope for in married life. Without her, this work could not have been completed.















TABLE OF CONTENTS


SECTION


PAGE


ACKNOWLEDGEMENTS . ii LIST OF TABLES . v LIST OF FIGURES . vi KEY TO TISSUES: NODES AND PETIOLES . xiv ABSTRACT . xv INTRODUCTION . 1


Systematics of the Saxifragaceae . Anatomical Work on the Saxifragaceae. Anatomical Work on New Zealand Genera. Anatomical Work on the Cunoniaceae. Rationale for the Present Study .


.1. . 3 . .6

. 10


MATERIALS AND METHODS . 14 RESULTS . 19


Tetracarpaea Hook . Ixerba A. Cunn . Bauera Banks . Anopterus Labill . Cuttsia F. v. Muell . . Abrophyllum Hook. f . Carpodetus J. R. & G. Forst . Corokia A. Cunn. Argophyllum J. R. & G. Forst . Donatia J. R. & G. Forst . Anodopetalum A. Cunn . Aphanopetalum Endl .


. 19 . 31 . 43 . 59 . 73 . 85 . 95 . . 110 . 127 . 141 . 150 . 160


DISCUSSION . 168

Anatomy of Twelve Australasian Genera . 168 Relationships of Ixerba . 173 Relationships of Anopterus . 176 Relationships of Cuttsia and Abrophyllum . 179 Relationships of Carpodetus . 181 Relationships of Corokia and Argophyllum . 185 Relationships Among the Escallonioideae . 190


iii







Possible Delimitation of the Escallonioideae . 193 Relationships of Tetracarpaea . 195 Relationships of Bauera. . 198 Relationships of Anodopetalum . 202 Relationships of Aphanopetalum . 204 Relationships of Donatia . 206 Australasian Genera and Geological History . 209

CONCLUSIONS . 211

SUMMARY . 220

APPENDIX . 221

LITERATURE CITED . 229

BIOGRAPHICAL SKETCH . 240















LIST OF TABLES


TABLE PAGE:

Table 1. Twelve Australasian genera classified according to Adolph Engler. 13 Table 2. Woody saxifragaceous species from Australasia examined anatomically. 18 Table 3. Anatomical features of eleven Australasian woody saxifragaceous genera. 169 Table 4. Specimens of Australasian woody Saxifragaceae examined anatomically. 222















LIST OF FIGURES

FIGURE PAGE

Figure 1. Leaf of Tetracarpaea tasmannica . 26 Figure 2. Vein ending of T. tasmannica . 26 Figure 3. Transverse sections of a node and petiole of T. tasmannica . 26 Figure 4. Transverse section of a leaf of T. tasmannica . 28 Figure 5. Transverse section of the abaxial epidermis of a leaf of T. tasmannica . 28 Figure 6. Transverse section of a leaf of T. tasmannica . 28 Figure 7. Marginal tooth of a leaf of T. tasmannica . 28 Figure 8. Transverse section of the secondary xylem of T. tasmannica . 30 Figure 9. Radial section of the secondary xylem of T. tasmannica . 30 Figure 10. Secondary xylem of T. tasmannica . 30 Figure 11. Tangential section of the secondary xylem of T. tasmannica . 30 Figure 12. Radial section of the secondary xylem of T. tasmannica . 30 Figure 13. Leaf of Ixerba brexioides . 38 Figure 14. Vein ending of I. brexioides . 38 Figure 15. Transverse sections of a node and petiole of I. brexioides . 38 Figure 16. Transverse section of a leaf of I. brexioides . 40 Figure 17. Optically anisotropic crystalloid from a leaf of I. brexioides . 40








Figure 18. Transverse section of the iidvein of a leaf of I. brexioides . 40 Figure 19. Paradermal section of the abaxial epidermis of a leaf of I. brexioides . 40 Figure 20. Transverse section of the abaxial epidermis of a leaf of I. brexioides . 40 Figure 21. Marginal crenation of a leaf of I. brexioides . 42 Figure 22. Paradermal section of a marginal crenation of a leaf of I. brexioides . 42 Figure 23. Transverse section of the secondary xylem of I. brexioides . 42 Figure 24. Radial section of the secondary xylem of I. brexioides . 42 Figure 25. Tangential section of the secondary xylem of I. brexioides . 42 Figure 26. Radial section of the secondary xylem of I. brexioides . 42 Figure 27. Leaf of Bauera rubioides . 52 Figure 28. Diversity of leaf shapes in B. capitata . 52 Figure 29. Vein ending of B. rubioides . 52 Figure 30. Diagrammatic representation of a node and the nodal pattern of B. rubioides . 54 Figure 31. Transverse section of a leaf of B. capitata . 56 Figure 32. Transverse section of a leaf of B. capitata showing prismatic crystals near a vascular bundle . 56 Figure 33. Transverse section of a leaf of B. sessiliflora . 56 Figure 34. Transverse section of a leaf of B. sessiliflora . 56 Figure 35. Paradermal section of the abaxial epidermis of a leaf of B. rubioides . 56 Figure 36. Transverse section of the abaxial epidermis of a leaf of B. capitata . 56


vii







Figure 37. Marginal serration of a leaf of B. rubioides . 56 Figure 38. Transverse section of a leaf of B. capitata . 56 Figure 39. Transverse section of the secondary xylem of B. rubioides . 58 Figure 40. Radial section of the secondary xylem of B. rubioides . 58 Figure 41. Radial section of the secondary xylem of B. sessiliflora . 58 Figure 42. Tangential section of the secondary xylem of B. sessiliflora . 58 Figure 43. Leaf of Anopterus glandulosus . 68 Figure 44. Vein ending of A. glandulosus . 68 Figure 45. Transverse section of a node of A. qlandulosus . 68 Figure 46. Transverse sections of a petiole of A. glandulosus . 68 Figure 47. Transverse sections of a petiole of A. macleayanus . 68 Figure 48. Transverse section of a leaf of A. glandulosus . 70 Figure 49. Transverse section of the midvein of a leaf of A. glandulosus . 70 Figure 50. Transverse section of the midvein of a leaf of A. macleayanus . 70 Figure 51. Transverse section of the abaxial epidermis of a leaf of A. glandulosus . 70 Figure 52. Marginal crenation of a leaf of A. glandulosus . 70 Figure 53. Paradermal section of a marginal crenation of a leaf of A. glandulosus . 70 Figure 54. Transverse section of the secondary xylem of A. glandulosus . 72 Figure 55. Radial section of the secondary xylem of A. glandulosus . 72


viii







Figure 56. Tangential section of the secondary xylem of A. glandulosus . 72 Figure 57. Radial section of the secondary xylem of A. glandulosus . 72 Figure 58. Leaf of Cuttsia viburnea . 80 Figure 59. Vein ending of C. viburnea . 80 Figure 60. Transverse sections of a node and petiole of C. viburnea . 80 Figure 61. Transverse section of a leaf of C. viburnea . 82 Figure 62. Crystal sand in the spongy mesophyll layer of a leaf of C. viburnea . 82 Figure 63. Transverse section of the midvein of a leaf of C. viburnea . 82 Figure 64. Paradermal section of the abaxial epidermis of a leaf of C. viburnea . 82 Figure 65. Marginal serration of a leaf of C. viburnea . 82 Figure 66. Transverse section of the secondary xylem of C. viburnea . 84 Figure 67. Radial section of the secondary xylem of C. viburnea . 84 Figure 68. Tangential section of the secondary xylem of C. viburnea . 84 Figure 69. Radial section of the secondary xylem of C. viburnea . 84 Figure 70. Leaf of Abrophyllum ornans . 92 Figure 71. Vein ending of A. ornans . 92 Figure 72. Transverse sections of a node and petiole of A. ornans . 92 Figure 73. Transverse section of a leaf of A. ornans. .94 Figure 74. Transverse section of a midvein of a leaf of A. ornans . 94 Figure 75. Transverse section of the abaxial epidermis of a leaf of A. ornans . 94







Figure 76. Transverse section of the secondary xylem of A. ornans . 94 Figure 77. Radial section of the secondary xylem of A. ornans . 94 Figure 78. Tangential section of the secondary xylem of A. ornans . 94 Figure 79. Leaf of Carpodetus serratus . 105 Figure 80. Domatium in the axil of a secondary vein of C. serratus . 105 Figure 81. Vein ending of C. serratus . 105 Figure 82. Transverse sections of a node and petiole of C. serratus . 105 Figure 83. Transverse section of a leaf of C. serratus . 107 Figure 84. Transverse section of a leaf of C. serratus . 107 Figure 85. Transverse section of a midvein of a leaf of C. serratus . 107 Figure 86. Marginal serration of a leaf of C. serratus . 107 Figure 87. Transverse section of the secondary xylem of C. serratus . 109 Figure 88. Transverse section of the secondary xylem of C. major . 109 Figure 89. Radial section of the secondary xylem of of C. arboreus . 109 Figure 90. Tangential section of the secondary xylem of C. serratus . 109 Figure 91. Leaf of Corokia macrocarpa . 120 Figure 92. Leaf of C. carpodetoides . 120 Figure 93. Vein ending of C. macrocarpa . 120 Figure 94. Transverse sections of a node and petiole of C. macrocarpa . 120 Figure 95. Transverse sections of a node and petiole of C. virgata . 122








Figure 96. Transverse section of a leaf of C. carpodetoides . 122 Figure 97. Transverse section of a midvein of a leaf of C. virgata . 122 Figure 98. Transverse section of a midvein of a leaf of C. macrocarpa . 122 Figure 99. Transverse section of a leaf of C. macrocarpa . 124 Figure 100. Paradermal section of the abaxial epidermis of a leaf of C. macrocarpa . 124 Figure 101. Transverse section of the abaxial epidermis of a leaf of C. virgata . 124 Figure 102. Multicellular, T-shaped trichome of C. macrocarpa . 124 Figure 103. Multicellular, T-shaped trichome of C. virgata . 124 Figure 104. Multicellular, T-shaped trichome of C. macrocarpa . 124 Figure 105. Pitting between the terminal cell and the uppermost stalk cell of a T-shaped trichome of C. macrocarpa . 124 Figure 106. Transverse section of the secondary xylem of C. buddleioides . 126 Figure 107. Transverse section of the secondary xylem of C. collenettei . 126 Figure 108. Radial section of the secondary xylem of C. collenettei . 126 Figure 109. Tangential section of the secondary xylem of C. whiteana . 126 Figure 110. Leaf of Argophyllum cryptophlebum.136 Figure 111. Vein ending of A. nullumense . 136 Figure 112. Transverse sections of a node and petiole of A. nullumense . 136 Figure 113. Transverse section of a leaf of A. nullumense . 138 Figure 114. Transverse section of the midvein of a leaf of A. nullumense . 138








Figure 115. Transverse section of the abaxial epidermis of a leaf of A. nullumense . 138 Figure 116. Pitting between the terminal cell and uppermost stalk cell of a T-shaped trichome of A. cryptophlebum . 138 Figure 117. Marginal serration of a leaf of A. cryptophlebum . 138 Figure 118. Transverse section of the secondary xylem of A. nullumense . 140 Figure 119. Radial section of the secondary xylem of A. ellipticum . 140 Figure 120. Tangential section of the secondary xylem of A. ellipticum . 140 Figure 121. Radial section of the secondary xylem of A. ellipticum . 140 Figure 122. Leaves of Donatia novae-zelandiae.147 Figure 123. Portion of a lamina of D. novaezelandiae . 147 Figure 124. Unilacunar, one-trace nodal pattern of D. novae-zelandiae . 147 Figure 125. Transverse section of a leaf of D. novaezelandiae . 147 Figure 126. Portion of lamina of D. novae-zelandiae proximal to the leaf apex . 147 Figure 127. Lignified parenchyma cells abaxial to vascular bundles in leaves of D. novae-zelandiae.149 Figure 128. Paradermal section of a leaf of D. novaezelandiae . 149 Figure 129. Transverse section of the abaxial epidermis of a leaf of D. novae-zelandiae . 149 Figure 130. Multicellular, uniseriate trichome of D. novae-zelandiae . 149 Figure 131. Transverse section of a stem of D. novaezelandiae . 149 Figure 132. Radial section of the secondary xylem of D. novae-zelandiae . 149


xii







Figure 133. Leaf of Anodopetalum biglandulosum . 157 Figure 134. Vein ending of A. biglandulosum . 157 Figure 135. Transverse sections of a node and petiole of A. biqlandulosum . 157 Figure 136. Transverse section of a leaf of A. biglandulosum . 159 Figure 137. Transverse section of a midvein of a leaf of A. biglandulosum . 159 Figure 138. Marginal crenation of a leaf of A. biglandulosum . 159 Figure 139. Transverse section of the secondary xylem of A. biglandulosum . 159 Figure 140. Radial section of the secondary xylem of A. biglandulosum . 159 Figure 141. Tangential section of the secondary xylem of A. biglandulosum . 159 Figure 142. Leaf of Aphanopetalum resinosum . 165 Figure 143. Transverse section of a stem and petiole of A. resinosum . 165 Figure 144. Transverse section of the avascular stipules of A. resinosum . 165 Figure 145. Vein ending of A. resinosum . 165 Figure 146. Transverse sections of a node and petiole of A. resinosum . 167 Figure 147. Transverse section of a leaf of A. resinosum . 167 Figure 148. Transverse section of a midvein of a leaf of A. resinosum . 167 Figure 149. Marginal serration of a leaf of A. resinosum . 167


xiii













Key to Tissues


Nodes


and Petioles


Sclerenchymo

Lignif led Porenchyma


I ~ ~


'! "'1 l,,r' I llz,1111ll
II l Ih


Xylem Collenchyma


Cork Phloem



From Metcalfe and Chalk (1950) with minor modification


xiv















Abstract of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy


COMPARATIVE ANATOMY AND SYSTEMATICS OF
TWELVE WOODY AUSTRALASIAN GENERA OF THE SAXIFRAGACEAE

By

MATTHEW HENRY HILS

AUGUST 1985

Chairman: Terry W. Lucansky
Major Department: Botany

Vegetative anatomical data are provided for twelve

woody saxifragaceous genera from Australasia. These data are used, where possible, to determine the taxonomic position of these plants. The twelve genera are Tetracarpaea, Ixerba, Bauera, Anopterus, Cuttsia, Abrophyllum, Carpodetus, Argophyllum, Corokia, Donatia, Anodopetalum and Aphanopetalum. Typically these taxa possess dorsiventral leaves with uniseriate epidermides and anomocytic stomatal apparatuses. The nodal pattern is either unilacunar, one-trace or trilacunar, three-trace. The wood possesses angular, solitary pores, long vessel elements with oblique, scalariform perforation plates, tracheids with spiral thickenings and sparse axial parenchyma. Cuttsia, Abrophyllum, Carpodetus, Ixerba, Anopterus, Corokia and Argophyllum possess most or all of eleven anatomical features of an archetypical woody







saxifrage. While wood anatomy is similar among Tetracarpaea, Bauera and an archetypical woody saxifrage, leaf anatomy is distinctive for each group. Donatia, Anodopetalum and Aphanopetalum possess few anatomical features of an archetypical woody saxifrage. Ixerba is anatomically isolated from the Brexioideae, but is similar to Anopterus in the Escallonioideae. Cuttsia and Abrophyllum are very similar anatomically and closely related. Anatomical data do not support the maintenance of the tribe Argophylleae of the Escallonioideae which includes Carpodetus, Corokia and Argophyllum. Carpodetus is more similar anatomically to Cuttsia and Abrophyllum than to Corokia and Argophyllum. Corokia and Argophyllum are very similar anatomically and probably closely related, but their taxonomic position remains obscure. Anatomical data support the union of the genus Argyrocalymma with Carpodetus, and the union of the genus Colmeiroa with Corokia. Tetracarpaea and Bauera are anatomically distinctive and isolated genera and may deserve familial status. Tetracarpaea is more closely allied to the Saxifragaceae based upon its wood anatomy, while Bauera is more closely allied to the Cunoniaceae because of its opposite leaves and foliaceous stipules. The nodal, leaf and wood anatomy of Anodopetalum is more similar to that of the Cunoniaceae than to that of the Saxifragaceae. Aphanopetalum and Donatia are readily distinguishable and isolated from the Saxifragaceae, but their taxonomic positions remain obscure. Donatia should probably be placed in its own family, but Aphanopetalum remains an enigma.


xvi














INTRODUCTION


Systematics of the Saxifragaceae

Although the family Saxifragaceae, sensu lato, is cosmopolitan, most species occur in temperate regions. The family contains trees, shrubs, vines, and herbs, and approximately 40 genera contain woody species. The taxonomic problems in the Saxifragaceae are numerous and well known (e.g., Cronquist, 1968; Dahlgren, 1975; Stern, 1974b; Takhtajan, 1980; Thorne, 1976, 1983), and occur at almost

every taxonomic level.

According to Engler (1928), the family consists of 15 subfamilies, 80 genera and approximately 1200 species. Thorne (1976, 1983) and Schulze-Menz (1964) also recognize a single large family that consists of 13-17 subfamilies and 78 to 80 genera. Other taxonomists have divided this group of plants into either a few families (Cronquist, 1968, 1981; Hutchinson, 1967) or many families (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan 1966, 1980, 1983). These smaller families usually correspond to Engler's (1928) subfamilies (Takhtajan, 1980), but may be much more inclusive (Cronquist, 1981).

Despite these differing opinions concerning the number of families, most taxonomists agree that the Saxifragaceae belong to the order Rosales (Engler, 1928; Schulze-Menz,









1964; Cronquist, 1981; Thorne, 1983), or the roughly equivalent order Saxifragales (Takhtajan, 1980). Dahlgren (1975, 1980, 1983), however, deviated from this consensus and split the various families into two superorders (Rosiflorae and Corniflorae) distributed among three orders (Cunoniales, Saxifragales, and Cornales). Hutchinson (1967) divided Saxifragaceae along herbaceous and ligneous lines, and placed the corresponding genera into his Saxifragales and Cunoniales, respectively.

In addition to these largely unresolved taxonomic problems, the placement and delimitation of several genera is questionable. Bauera, for example, has been placed in the Saxifragaceae (Engler, 1928), the monogeneric Baueraceae (Hutchinson, 1967), and the Cunoniaceae (Cronquist, 1981). Aphanopetalum is another genus often placed in the Cunoniaceae, but its affinities are questionable (Dickison, 1980b). Donatia is also enigmatic. Engler (1890) originally placed this genus in the Saxifragaceae, but later (1928) was uncertain of its affinities. Other taxonomists have placed Donatia in the Stylidiaceae (Mildbraed, 1907; Thorne, 1976, 1983; Dahlgren, 1975, 1980, 1983) or in the monogeneric Donatiaceae (Cronquist, 1981). Another bewildering genus, Corokia, has been shuttled among the Saxifragaceae (Engler, 1928), Escalloniaceae (Takhtajan, 1980), Cornaceae (Cronquist, 1981), and Corokiaceae (Dahlgren, 1983). In addition, Corokia carpodetoides was originally the basis of a separate genus, Colmeiroa (Engler, 1928), although Smith








(1958) more recently has combined this genus with Corokia. Similarly, the genus Argyrocalymma, endemic to New Guinea, has been reduced to a section of the genus Carpodetus (Engler, 1928; Reeder, 1946; Schlechter, 1914). Hydrangea also has been divided into two sections, Hydrangea and Cornidia (McClintock, 1957), and each of these sections has at times been elevated to the generic level (Small and Rydberg, 1905).


Anatomical Work on the Saxifragaceae

Early anatomical studies of the Saxifragaceae are those of Thouvenin (1890) and Holle (1893). These workers noted that, despite their anatomical heterogeneity, the woody saxifragaceous genera typically share the following characteristics: scalariform perforation plates, three vascular traces at the base of a petiole, and a stomatal apparatus without subsidiary cells. In addition, trichomes vary from simple, unicellular to branched, multicellular or glandular, multicellular types. Prismatic crystals, druses, raphides, or crystal sand also occur.

Thouvenin (1890) recorded anatomical descriptions of

stems and leaves for Ixerba, Bauera, Anopterus, Abrophyllum, and Donatia along with other mostly herbaceous Saxifragaceae. He concluded that the escallonioid and brexioid genera (i.e., Ixerba, Anopterus, and Abrophyllum) were a central group and all other tribes should be arranged around them. Donatia and two other genera of the herbaceous tribe Saxifrageae were thought to provide a link to Brexieae








(through Roussea) because these genera possess secretory cells in the internal portions of the cortex.

Holle (1893) emphasized the anatomy of stem, leaf, and cork of various herbaceous and woody saxifrages including Bauera, Anopterus, Abrophyllum, Argophyllum, Carpodetus, and Anodopetalum. Within all of these genera, cork originates subepidermally. Holle grouped Argophyllum and Abrophyllum together because they lacked crystals. He also placed Carpodetus and Anopterus relatively close together because they possess druses and simple hairs. Anodopetalum and Bauera were isolated from the other four genera and separated from one another because the former has both simple crystals and druses, while the latter only has simple crystals.

Zemann (1907) elaborated on the anatomy of Argophyllum in her monograph of the genus. She divided Argophyllum into two sections, Brachycalyx and Dolichocalyx, based upon the length of the calyx relative to the corolla. Zemann also noted that the leaves of species in section Brachycalyx either possess a bi- to triseriate hypodermis or palisade cells that are very short and square in transection, whereas the leaves of species in section Dolichocalyx lack a hypodermis and possess columnar palisade cells.

In his systematic anatomical summary of the dicotyledons, Solereder (1908) considered all of the above genera to be saxifragaceous. He also included the monotypic genus Colmeiroa among the Saxifragaceae, and noted that according to Engler, this genus possesses two-armed trichomes.





5


Watari (1939) investigated the leaf anatomy of some Saxifragaceae, including Ixerba, Bauera, Corokia, and Carpodetus. Except for Bauera, these genera possess penninerved, simple leaves, trilacunar nodal patterns and bifacial petioles. Bauera possesses palmately compound leaves, unilacunar nodal patterns and bifacial petioles. In addition, the foliar vascular bundles of these genera exhibit radial rows of xylary elements and fairly regular to irregular starch sheaths adjacent to the pericycle (Watari, 1939). Swamy (1954) studied nodal and petiolar vasculature of the Escallonioideae and reported unilacunar, one-trace nodal patterns in Abrophyllum and Tetracarpaea and trilacunar, three-trace nodal patterns in Ixerba, Anopterus, Cuttsia, Argophyllum, Corokia and Carpodetus. A pentalacunar nodal pattern was noted for Argophyllum laxum. Swamy (1954) indicated that the petiole patterns were similar among certain groups of genera with unilacunar and trilacunar nodal configurations.

As part of a comparative study of the wood anatomy of the Moraceae and alleged allies, Tippo (1938) briefly described the wood of the Hydrangeaceae, Grossulariaceae, sensu stricto, and Escalloniaceae based upon a few species from each family. All three families are characterized by mostly solitary, angular, thin-walled, small-diameter pores. Vessel elements are medium to long and have predominantly scalariform perforation plates. Imperforate elements are mostly tracheids and fiber-tracheids and axial parenchyma is sparse. Xylem rays are heterogeneous with sheath cells









usually present. He concluded that a close relationship exists between the Escalloniaceae and Grossulariaceae, and somewhat less affinity occurs between the Escalloniaceae and Hydrangeaceae. Also, the family Escalloniaceae is the most advanced of these three families.

Metcalfe and Chalk (1950), in their survey of the

vegetative anatomy of the dicotyledons, did the last broad treatment of the anatomy of the Saxifragaceae. Based upon their anatomical summaries, they placed Bauera in the Saxifragaceae, sensu stricto, Anopterus, Abrophyllum, Argophyllum, and Carpodetus in the Escalloniaceae, Corokia in the Cornaceae, Anodopetalum in the Cunoniaceae, and Donatia in the Stylidiaceae.


Anatomical Work on New Zealand Genera

Certain studies of the woody plants of New Zealand

include the genera Carpodetus, Ixerba, and Corokia (Brook, 1951; Butterfield and Meylan, 1976; Meylan and Butterfield, 1978; Morrison, 1953; Ohtani, Meylan and Butterfield, 1983; Patel, 1973a, 1973b; Robinson and Grigor, 1963; Sampson and McLean, 1965). Some of these studies have provided systematic conclusions based upon anatomical data (Brook, 1951; Patel, 1973a, 1973b). Brook (1951) studied the vegetative anatomy of the endemic Carpodetus serratus and supported its placement in the Escalloniaceae because of its wide rays, vessel elements with scalariform perforation plates, and large bordered pits in the wood fibers. Patel (1973b) investigated the wood anatomy of the









Escalloniaceae, including Carpodetus serratus and the monotypic Ixerba brexioides. Both species possess narrow, angular pores, and vessel elements with scalariform perforation plates. Xylem ray tissue is heterogenous type II. The wood of Carpodetus, however, possesses some very wide rays, whereas the wood of Ixerba possesses only narrow rays. Patel (1973b) concluded that both genera belonged in the Escalloniaceae, although Ixerba was less primitive than Carpodetus.

Although Corokia is widely distributed in the South Pacific Islands, its center of diversity is New Zealand (Allan, 1961). In his study of the Cornaceae Sertorius (1893) described the leaf and stem anatomy of two species of Corokia. He noted, as have other workers (Eyde, 1966; Weiss, 1890), the distinctive, multicellular, T-shaped trichomes in this genus. Sertorius further described the leaves of Corokia with their uni- to biseriate palisade mesophylls, uniseriate epidermides, and sclerenchymatous bundle sheaths surrounding the vascular bundles. He characterized Corokia wood as fine-textured, consisting of numerous, thick-walled fibers bearing circular-bordered or simple pits and solitary, narrow, angular pores. Vessel perforations are scalariform with 10-20 thin bars per plate.

Later studies of the wood anatomy of the Cornaceae (Adams, 1949; Li and Chao, 1954; Patel, 1973a) also have provided descriptions of some species of Corokia. Adams (1949) placed this genus in the Cornaceae near Cornus. While Li








and Chao (1954) acknowledged some affinity between Corokia and Cornus, they also noted a close similarity between the wood of Corokia and the wood of Saxifragaceae. Patel (1973a) noted septate fiber-tracheids in the wood of Corokia, and concluded that affinities with either the Cornaceae or the Escalloniaceae were unsatisfactory for this problematic genus. Descriptions of the distribution and development of anomycytic stomatal patterns on the leaves and flowers of Corokia also have been made (Bhatnagar, 1973; Kapil and Bhatnagar, 1974).

Eyde (1966) excluded Corokia from the Cornaceae based upon floral morphology and anatomy. He argued for an affinity between Corokia and Argophyllum based upon floral anatomy and the presence of multicellular, T-shaped trichomes and septate fiber-tracheids in both genera. Although both genera are included in Engler's (1928) Saxifragaceae, subfamily Escallonioideae, Eyde questioned the validity of this taxonomic arrangement.

Another genus that occurs in New Zealand is Donatia.

Mildbraed (1907) used vegetative and reproductive anatomical characteristics and traditional morphological characters to include Donatia in the Stylidiaceae within its own subfamily, Donatioideae. Data from floral anatomy (Carolin, 1960) and embryology (Philipson and Philipson, 1973) also support inclusion of Donatia in the Stylidiaceae, although Carolin discussed the possibility that this family may be closer to the Saxifragaceae rather than the Campanulaceae to which it is often allied (Cronquist, 1981). Other work on









the vegetative anatomy of Donatia (Chandler, 1911; Rapson, 1953) has revealed multicellular, uniseriate trichomes, tannin cells, a lignified endodermis, vessel elements with scalariform perforation plates and sclerenchyma associated with the foliar veins. Based upon these data, these workers support the separation of the Donatiaceae from the Stylidiaceae, although they emphasize that a close taxonomic relationship exists between these two families. Both studies also rejected any saxifragaceous affinities for Donatia. Carlquist (1969), however, has noted morphological similarities between Donatia and the Saxifragaceae.


Anatomical Work on the Cunoniaceae

The family Cunoniaceae is usually regarded as a close relative of the Saxifragaceae (Cronquist, 1981; Engler, 1928; Thorne, 1983). Recent comparative floral and vegetative anatomical studies in the Cunoniaceae (Dickison, 1975c, 1975d, 1980a, 1980b) support the inclusion of Anodopetalum in this family but are inconclusive regarding the placement of Bauera and Aphanopetalum. Dickison (1980a) and earlier workers (Dadswell and Eckersley, 1935; Ingle and Dadswell, 1956) place Anodopetalum among the advanced members of the Cunoniaceae because the wood has numerous vessels commonly distributed in multiples with vessel elements connected by mostly simple perforation plates and opposite to alternate intervascular pitting. Fiber-tracheids, weakly heterogeneous xylem ray tissue and aggregated axial parenchyma also are present.









Dickison (1980a, 1980b) studied the nodal and wood

anatomy of Bauera sessiliflora. The presence of unilacunar, one-trace nodes and lack of interpetiolar stipules made an affinity to the Cunoniaceae doubtful. Nevertheless, he noted that the wood anatomy is not inconsistent with that found in other advanced cunoniaceous woods. Based upon floral anatomy, Dickison (1975b) supported the inclusion of Bauera in the Saxifragaceae, whereas Bensel and Palser (1975c) favored a placement in the Cunoniaceae. These workers have emphasized the need for further critical study of Bauera. Carey (1938) reported a brief anatomical description of the leaves of Bauera rubioides from two different habitats, and characterized this species as sclerophyllous.

Based upon study of leaf and nodal anatomy in Aphanopetalum, Dickison (1975c, 1980b) found no affinity of this genus to the Cunoniaceae because of its unilacunar, onetrace nodes, lack of stipules, leaf epidermal cells with undulate anticlinal walls, and its scrambling viny habit. He offered no other taxonomic placement for this genus.


Rationale for the Present Study

The Saxifragaceae, sensu lato, are certainly in need of systematic study. Stern (1974b) asserted that our failure to sort out plants assigned to Saxifragaceae has given rise to various classification schemes typically based upon similar, morphological data which emphasize floral morphology. He stated that solutions to the taxonomic problems will develop only from analysis of new data and novel methods of









interpreting old data rather than from reworking old data using time-worn procedures. He suggested intensive studies

in plant anatomy as one means of securing new data. The application of comparative anatomical data to the solution of taxonomic and phylogenetic problems in plants is wellknown (Bailey, 1944; Carlquist, 1961; Metcalfe and Chalk, 1950, 1979, 1983; Stern, Brizicky, and Eyde, 1969).

Details of vegetative anatomy, particularly wood anatomy, have been shown to be especially useful in taxonomic and phylogenetic interpretations of various plant groups without

bias or preconception from earlier classification systems (Dickison, 1975a; Stern, 1978b; Tippo, 1938). A recent

application of the comparative anatomical method in the Saxifragaceae is a study of Hydrangea (Stern, 1978a).

The purpose of this work is to provide vegetative

anatomical and morphological data, especially wood anatomy, for twelve woody saxifragaceous genera that occur in Australia, New Zealand, New Guinea, New Caledonia and some smaller South Pacific islands, and to use these data, where

possible, to determine the taxonomic position and evolutionary relationships of these plants. Although various anatomical studies of the Saxifragaceae have been done, a comparative, systematic study of the vegetative anatomy of these twelve genera is lacking. The generic level has been

chosen as the unit of study to avoid any bias from previous classification systems. The twelve genera are listed in Table 1 according to Engler's (1928) classification system.








This system is presented as a convenient point of reference because it is still the most comprehensive treatment of the Saxif ragaceae. Because of the relatively similar geological history of the above Australasian land masses (Raven and Axelrod, 1972), these 12 genera may have undergone similar evolutionary influences and thus may exhibit many anatomical

similarities. The present anatomical study should provide new perspectives to aid in delineating taxonomic affinities

between and among these plants from the antipodes.










Table 1. Twelve Australasian genera classified according to Engler (1928). Distribution information in parentheses: A, Australia; NC, New Caledonia; NG, New Guinea; NZ, New Zealand; PI, Other Pacific Islands; SA, South America; T, Tasmania.



SAXIFRAGACEAE

Subfamily Tetracarpaeoideae

Tribe Tetracarpaeeae
Tetracarpaea (T)

Subfamily Brexioideae

Tribe Brexieae
Ixerba (NZ)

Subfamily Baueroideae

Tribe Bauereae
Bauera (A,T)

Subfamily Escallonioideae

Tribe Anoptereae
Anopterus (A,T)

Tribe Cuttsieae
Cuttsia (A)
Abrophyllum (A)

Tribe Argophylleae
Argophyllum (A,NC)
Corokia (A,NZ,PI)
Carpodetus (NG,NZ)

Incertae sedis: Donatia (NZ,SA,T)

CUNONIACEAE

Tribe Spiraeanthemeae
Aphanopetalum (A)

Tribe Cunonieae
Anodopetalum (T)















MATERIALS AND METHODS

Preserved leaves, stems and wood, and dried wood of twelve woody saxifragaceous genera from Australasia were used in this study (Table 2). Only dried leaf and stem material of Corokia carpodetoides was available for study. These plant materials are part of an extensive collection of specimens of woody Saxifragaceae gathered through collection, correspondence and exchange by Professor William Louis Stern since the late 1960's. Collection information for individual specimens is included in the appendix (Table 4). The authorities for the names of the species studied are listed in Table 2.

Standard microtechnical methods were used and are similar to those followed by Stern, Sweitzer and Phipps (1970), so that direct comparisons could be made between the present study and recent studies of the woody Saxifragaceae (Stern, 1974a, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979a, 1979b). Dried wood specimens were boiled in water to eliminate air in the tissue, and the blocks were stored in a 50:50 mixture of 95% ethanol and glycerin. Fluid-preserved wood specimens were washed in water and kept in the same storage solution. Transverse, radial, and tangential sections of unembedded wood samples of each specimen were made with a sliding microtome.








Similar sections were prepared from a few celloidin-embedded wood samples. Sections were stained with Heidenhain's iron alum hematoxylin and counterstained with safranin (Johansen, 1940). Because ammoniacal iron alum dissolves oxalate crystals (Metcalfe, 1983), a few sections were dehydrated and mounted without staining. Wood slivers were macerated using Jeffrey's fluid (50:50 mixture of 10% nitric acid and 10% chromic acid) and stained with safranin (Johansen, 1940). Wood sections and macerations were mounted on glass slides with Canada balsam or Permount.

Dried leaves and stems were boiled in water to

reconstitute the tissues, fixed in a formalin-acetic acidalcohol solution and stored in 70% ethanol. Fluid-preserved leaves and stems also were stored in 70% ethanol. Leaves were cleared using 5% NaOH, washed in distilled water and bleached with a saturated aqueous solution of chloral hydrate (Arnott, 1959). Fully cleared leaves were washed in distilled water, stained with safranin, dehydrated and mounted on glass slides with Permount. Transverse and paradermal sections of paraffin-embedded leaves were cut on a rotary microtome, affixed to a glass slide with a modified Haupt's adhesive (Bissing, 1974), stained with iron alum hematoxylin and safranin and mounted with Canada balsam. A few leaf sections were mounted unstained to detect crystals.

Freehand sections were cut of at least two nodes from a stem and at the proximal (point of attachment to stem), median (a midpoint on petiole), and distal (near lamina) portions of at least two petioles. These sections were








treated with an aqueous phloroglucinol solution followed by concentrated HCl to demonstrate lignified regions. The nodal regions of the stems and petioles of some specimens also were cleared and stained using the above clearing

procedure. Species with very short nodes and small petioles were embedded in paraffin and sectioned with a rotary microtome. These sections were treated similarly to the paraffin-embedded leaf sections.

Anatomical analyses of leaves, including vascular

architecture, cell and tissue types, trichomes and surface

features (i.e., stomata, hydathodes, etc.), followed the terminology used. by Hickey (1979), Metcalfe (1979), Theobald, Krahulik and Rollins (1979), and Wilkinson (1979).

Although developmental studies were not performed, the term biseriate epidermis was used to describe both the outermost cell layer and the subjacent cell layer in leaves where these two layers occur to be consistent with the terminology

of other recent studies of the woody Saxifragaceae (Stern, 1974a, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979a, 1979b). Measurements were made of both the long and short axes (length and width) of ten pairs of guard cells for each specimen. The nodal patterns and vasculation

of the petiole were diagrammed and described following the summaries by Howard (1979a, 1979b).

Characterization of the wood followed the diagnostic features set forth by Tippo (1941) and the terminology

advocated by the Committee on Nomenclature, International Association of Wood Anatomists in the Multilingual Glossary









of Terms Used in Wood Anatomy (1964). The only exception is

the use of the term marginal parenchyma in place of either terminal or initial axial parenchymna. The following measurements were made for each specimen: 1) pore distributions were percentages based upon counts taken from ten 0.2 mm2 microscopic fields; 2) tangential vessel diameters were determined from 50 measurements taken from cross sections; 3) wall thicknesses were based upon measurements of ten vessels and ten imperforate tracheary elements taken from cross sections; 4) lengths of cells were based upon measurements from end to end of 50 vessel elements and 50

imperforate tracheary elements taken from macerated wood; 5) number of bars per perforation plate were counted from thirty scalariform perforation plates; 6) end-wall angles of vessel elements, relative to the vertical axis of the

cell, were measured for ten cells from tangential sections using an ocular goniometer; 7) vertical diameters of

intervascular pits were determined from ten pits viewed in radial section; 8) length and width of xylem rays were measured from ten rays viewed in tangential section. Unless noted otherwise, the measurements reported below represent an average for all the species examined in a genus.





18





Table 2. Woody saxifragaceous species from Australasia
examined anatomically: d, dried material;
p, fluid-preserved material.



SPECIES WOOD LEAVES


Abrophyllum ornans Hook. f. dp p

Anodopetalum biglandulosum A. Cunn. p p

Anopterus glandulosus Labill. dp p
Anopterus macleayanus F.v. Muell. dp p

Aphanopetalum resinosum Endl. p

Argophyllum cryptophlebum Zemann p p
Argophyllum ellipticum Labill. d
Argophyllum nullumense R.T. Baker p p

Bauera capitata Seringe p
Bauera rubioides Andr. dp p
Bauera sessiliflora F.v. Muell. dp p

Carpodetus sp. p p
Carpodetus arboreus
(K. Schum. et Lauterb.) Schltr. d
Carpodetus major Schltr. d
Carpodetus serratus J.R. & G. Forst. dp p

Corokia buddleioides A. Cunn. d
Corokia carpodetoides
(F.v. Muell.) L.S. Smith d
Corokia collenettei Riley d
Corokia macrocarpa Kirk p
Corokia virgata Turrill p
Corokia whiteana L.S. Smith d

Cuttsia viburnea F.v. Muell. dp p

Donatia novae-zelandiae Hook. f. p p

Ixerba brexioides A. Cunn. dp p

Tetracarpaea tasmannica Hook. p p















RESULTS

Tetracarpaea Hook.

Introduction

The monotypic genus Tetracarpaea was described from

specimens of T. tasmannica and placed in the Cunoniaceae by William J. Hooker in 1840. The generic name refers to its distinctive four carpellate apocarpous gynoecium (Hooker, 1840). The genus is endemic to and occurs throughout most of Tasmania, but is absent from the east and northwest floristic zones of the island (Mosley, 1974b). Plants of T. tasmannica are small, erect bushy shrubs that commonly grow in subalpine habitats and may attain a height of approximately one foot (Bentham, 1864). These plants bear small, exstipulate, alternate or scattered leaves and four-merous, hypogynous, flowers arranged in racemes.

Joseph D. Hooker (1865) positioned Tetracarpaea in his tribe Escallonieae, while Bentham (1864) placed this genus in his tribe Cunonieae. Both tribes are included in their order Saxifrageae (= the modern family Saxifragaceae [Stearn, 1965]). Engler (1890) placed Tetracarpaea in his inclusive rosalean family Saxifragaceae, first within the subfamily Escallonioideae, but later (1928) in its own subfamily, Tetracarpaeoideae. Schulze-Menz (1964) and Thorne (1976, 1983) have supported the later Englerian








treatment, but other workers have diverged from this view. Hutchinson (1967) included Tetracarpaea in the Escalloniaceae of his Cunoniales, while Cronquist (1981) placed it in his larger rosalean family, Grossulariaceae. Takhtajan (1966, 1980) placed this genus in his Saxifragales, initially (1966) in the monotypic Tetracarpaeaceae, but recently (1980, 1983) in his Escalloniaceae. Airy Shaw (in Willis, 1973) and Dahlgren (1975, 1980, 1983) also considered this genus to form the basis of a monotypic family, and Dahlgren has tentatively placed Tetracarpaea in his Cornales.


Observations

Tetracarpaea possesses small, ovate, serrate, alternate leaves. The small teeth of the leaf margin are rounded. The petiole is very short and almost indistinguishable because the lamina tapers gradually toward the point of attachment of leaf to stem. Venation is simple craspedodromous with a prominent midrib and conspicuous secondary veins that terminate at the leaf margin (Fig. 1). Vein areole development is incomplete to lacking. The veinlets are usually straight and tapered, but may be somewhat forked (Fig. 2). Vein endings consist of two to four tracheids with helical thickenings (Fig. 2). Infrequently these tracheids are accompanied by fiber-tracheids with thicker walls and oval bordered pits.

The nodal pattern is unilacunar, one-trace, and a single collateral vascular bundle enters the base of a








petiole (Fig. 3). Two collateral bundles separate from the midvein near the base of a petiole, and a third bundle splits from the midvein at a midpoint in a petiole. A median section of a petiole, therefore, shows four collateral bundles (Fig. 3). The outermost two bundles represent the first two bundles that diverge from the midvein. The larger of the two, central bundles represents the petiolar midvein, while the smaller bundle represents the third bundle to diverge from the midvein. All four bundles enter the lamina distally (Fig. 3).

Leaves are dorsiventral with a well-differentiated, triseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 4). The cells of the innermost layer of the palisade layer are sometimes shorter than the other typically columnar cells of this layer, but are distinct from the cells of the spongy mesophyll. The spongy mesophyll has more cell layers but is approximately the same thickness as the palisade layer (Fig. 4). The spongy mesophyll cells have various shapes and sizes and are loosely arranged with numerous, large intercellular spaces. The two cell layers adjacent to the abaxial epidermis are more tightly arranged and have smaller and fewer intercellular spaces than the remainder of the spongy mesophyll (Figs. 4 & 5). Druses commonly occur in the cells of the spongy mesophyll (Fig. 6).

The small, arc-shaped vascular bundles of a leaf are collateral (Fig. 4). Very little secondary growth is visible within these bundles. Although bundle sheaths and








bundle sheath extensions are lacking, thick-walled abaxial fibers are present adjacent to the primary phloem of the midvein (Fig. 4).

Both the adaxial and abaxial epidermal layers are uniseriate and composed of variously-shaped cells with evenly-thickened walls (Fig. 4). In surface view these cells also are variously-shaped (polygonal to elongate), and possess curved, evenly thickened, anticlinal walls. Both epidermal layers lack trichomes and are covered by a very thick cuticle (approximately 10 um; Fig. 5).

Abundant stomata are restricted to the abaxial

epidermis, and the stomatal apparatus is anomocytic. In surface view the guard-cell pair possesses an almost circular outline, while the individual guard cells are reniform. Guard-cell pairs average 30 um in length and 26 um in width (length/width ratio 1.15). In transection the guard cells are oval to circular and each cell bears a prominent, cuticular horn that represents the outer ledge overarching a stoma (Fig. 5).

In cleared leaves the marginal teeth have a tumid appearance indicating the presence of hydathodes. A prominent vein extends nearly to the tooth apex (Fig. 7), but water pores associated with functional hydathodes are not distinguishable. Apical cells of the leaf teeth stain lighter in cleared leaves than surrounding cells which may indicate thinner cell walls (Fig. 7). The densely stained cytoplasm of these cells in paradermal sections of uncleared leaves may signify that this tissue is glandular.









Tetracarpaea wood is diffuse porous with poorly

discernible growth rings (Fig. 8). The wood is very finetextured with numerous angular pores (range 180-445/mm2,I x= 309) that have extremely small tangential diameters (range 11.7-23.4 um, _X= 16) and walls 2.1-4.2 um (R=2.8) thick. Pores are predominately solitary (80%) with radial multiples

(3%) and clusters (17%) of two to three pores resulting mostly from overlapping vessel element end walls. Rarely clusters of four or five pores are observed. vessels are difficult to distinguish from axial parenchyma in slide Aw

27721 because the parenchyma is devoid of contents, and the slide has been stained with safranin only. Thus, counts of the number of pores per f ield are greatly inflated in this specimen. Vessel elements are of medium length (range 213455 um, x= 354), and very fine spiral thickenings are present in some of these cells. Vessel element end walls are oblique, and end-wall angles range from 0-220 (R~=10). Perforation plates are exclusively scalariform, possess 5 to

18 bars per plate (Rc= 8), and the perforations are completely bordered (Fig. 9). Scalariform perforation plate

bars are thick and may be branched in various ways to form a reticulate pattern, Occasionally two scalariform perforation plates occur in a vessel element end wall. Scalariform, transitional to opposite intervascular pitting is

confined mostly to overlapping end walls of contiguous vessel elements (Fig. 9). Pit diameter is minute and ranges from 3.2-4.2 um (R= 3.3).








Tracheids bear circular-bordered pits with oval apertures that extend slightly beyond the margins of the pit border (Fig. 9). The diameter of these pits is similar to that of the intervascular pits. Tracheids are extremely short (range 325-520 um, R= 396). Tracheid walls are relatively thick and range from 2.1-6.3 um (R= 4). Very fine spiral thickenings are present in some of these cells (Fig. 10).

Axial parenchyma is sparse and apotracheal diffuse or diffuse-in-aggregates. Vessel to axial parenchyma pitting is scalariform. No ergastic substances are noted in these cells.

Although the xylem ray system consists of homocellular uniseriate rays of upright cells and heterocellular uni- and biseriate rays, uniseriate rays predominate. Most heterocellular rays are biseriate (Fig. 11), although these rays are two cells wide for only 1-4 cells of their length. Ray height ranges from 1-17 cells (.07-.75 mm) for homocellular rays and from 7-31 cells (.28-1.22 mm) for heterocellular rays. Ray cells contain dark brown deposits and numerous starch grains (Figs. 9 & 11). Perforated ray cells are infrequent (Fig. 12), while sheath cells and crystals are absent. Vessel to ray parenchyma pitting is opposite to alternate. No fusion of rays is noted.






























Figure 1. Leaf of Tetracarpaea tasmannica. X10. Note simple craspedodromous venation. Figure 2. Vein ending of T. tasmannica. X175. Figure 3. Transverse sections of a node (a) and proximal
(b), median (c) and distal (d) sections of a petiole of T. tasmannica. X30.


Details: t, tracheids.





lipkv-

























Figure 4. Transverse section of a leaf of Tetracarpaea tasmannica. X110. Note fibers abaxial to the midvein.

Figure 5. Transverse section of the abaxial epidermis of a leaf of T. tasmannica. X700. Note the guard-cell pair with prominent cuticular horns (arrows).

Figure 6. Transverse section of a leaf of T. tasmannica. X437. Note druses in the spongy mesophyll.

Figure 7. Marginal tooth of a leaf of T. tasmannica. X110.


Details: ab, abaxial epidermis; ad, adaxial epidermis; c, cuticle; d, druses; f, fibers; gc, guard cell; m, midvein; pl, palisade layer; sl, spongy mesophyll layer.

































ab


V
c


Aft " - /


NW


Aim

J























Figure 8. Transverse section of the secondary xylem of Tetracarpaea tasmannica. X175. Note solitary, angular pores.

Figure 9. Radial section of the secondary xylem of T. tasmannica. X437.

Figure 10. Secondary xylem of T. tasmannica. X 700. Note tracheids with spiral thickenings (arrows).

Figure 11. Tangential section of the secondary xylem of T. tasmannica. X175. Note uni- and biseriate rays.

Figure 12. Radial section of the secondary xylem of T. tasmannica. X437. Note perforated ray cell with scalariform perforation plate.


Details: p, pores; pi, pits; pc, perforated ray cell; pp, perforation plate; r, ray parenchyma; t, tracheids; v, vessel element.












V r



p.



* a 6 '. A
taat








I e









It.o
i t dhl 0'




~ 1C~,'~~3~~a~TE~IC 3eS"~~''U7/r~s~RS ~+;O










Ixerba A. Cunn.

Introduction

The monotypic genus Ixerba was described by A. Cunningham (1839) from specimens collected in Wangaroa, New Zealand. He based the generic name on an anagram of Brexia Thouars to emphasize an affinity which he believed to exist between the two genera. Ixerba brexioides is endemic to North Island, New Zealand and occurs throughout Aukland and northern Hawke's Bay Districts in hilly lowland and montane forests (Allan, 1961; Cheeseman, 1914, 1925). Plants of Ixerba are small trees with linear, opposite, alternate, or whorled, exstipulate leaves (Allan, 1961; Cheeseman, 1925). The five-merous, hypogynous, flowers are arranged in panicles, and the fruit is a capsule.

Various taxonomists have agreed with Cunningham's view that Ixerba and Brexia are closely related and have placed these genera in the subfamily Brexioideae of the Saxifragaceae (Engler, 1928; Schulze-Menz, 1964; Thorne, 1976) or the Brexiaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966). Hooker (1865), however, included Ixerba in the tribe Escallonieae of the Saxifragaceae, and Engler (1890) originally placed it in the Escallonioideae of the Saxifragaceae. Recently, Thorne (1983) has changed his placement of Ixerba to the Escallonioideae. Hutchinson (1967) and Takhtajan (1980, 1983) have advocated a position in the Escalloniaceae for Ixerba, while Cronquist (1981) placed it in his Grossulariaceae.










Observations

Ixerba possesses narrowly oblong to elliptic, alternate, opposite or whorled leaves that bear blunt, widelyspaced crenations. Venation is semicraspedodronous with a prominent midrib and conspicuous secondary veins that branch

to extend near the leaf margin and arch distally to join with superadjacent secondary veins (Fig. 13). Vein areole

development is incomplete. Veinlets vary, from simple and straight to once, twice, or three times branched (Fig. 14). The vein endings may be branched or unbranched and tapered, and are composed of helically thickened tracheids that may be elongate, curved, forked, or irregularly shaped (Fig. 14). These tracheids often possess protuberances which are characterized by helical thickenings that differ in orientation from the thickenings in the remainder of the cell. Parenchymatous bundle-sheath cells and thick-walled fibers are associated with the vascular tissues in most vein endings.

The nodal pattern is trilacunar, three-trace, and three collateral bundles enter a petiole (Fig. 15). These bundles fuse laterally to produce a single, large flattened bundle

in the center of the petiole in median and distal sections (Fig. 15). In some petioles a median section reveals that one lateral bundle fuses with the central bundle before the other lateral bundle. In these latter petioles the large flattened bundle is only visible in more distal sections of

the petiole. A very small collateral bundle splits from









each end of the large central petiolar bundle. These small accessory bundles occur lateral to the central bundle (Fig. 15).

Leaves of Ixerba are dorsiventral with a welldeveloped, bi- to triseriate palisade layer and a highly lacunose spongy mesophyll layer (Fig. 16). The two uppermost layers of palisade cells are typically columnar and tightly appressed, while the cells of the innermost layer are highly variable in shape, often widely-spaced, and intergrade with the adjacent spongy mesophyll cells (Fig. 16). The cells of the spongy mesophyll are highly variable in shape and size and separated by numerous, large intercellular spaces. One or two large, yellowish, optically anisotropic, crystalloid inclusions occur in most cells of the palisade and spongy layers and both epidermides (Figs. 16 & 17). These inclusions probably are not calcium oxalate crystals because they did not dissolve in ammoniacal iron alum.

All vascular bundles of a leaf are collateral and

surrounded by a bundle sheath. The large, flattened, arcshaped, midvein, with well-developed secondary growth, is almost completely surrounded by thick-walled, lignified parenchyma cells (Fig. 18). This large bundle also possesses adaxial and abaxial bundle sheath extensions composed of parenchyma and collenchyma cells. The smaller vascular bundles (secondary and minor veins) exhibit no secondary growth, have a few sclerenchyma cells adjacent to the








primary vascular tissues, are surrounded by a parenchymatous bundle sheath and lack bundle sheath extensions (Fig. 16).

Both the adaxial and abaxial epidermal layers are uniseriate, and consist of mostly square to rectangular cells in transection (Fig. 16). The outer periclinal walls of all epidermal cells are slightly thickened. In surface view the epidermal cells are square to polyhedral with straight anticlinal walls. The cuticle is very thick (>5 um), and trichomes are absent.

Abundant stomata are restricted to the abaxial epidermis, and the stomatal apparatus is anomocytic (Fig. 19). In surface view guard cells are reniform, and guard-cell pairs are virtually circular in outline with an average length of 36 um and a width of 34 um (length/width ratio 1.06). In transection guard cells are oval, and each cell bears a small, thin, cuticular horn that represents the outer ledge overarching a stoma (Fig. 20).

Marginal crenations of Ixerba leaves contain glands that are characterized by thick-walled parenchyma cells arranged in regular files (Fig. 21). In paradermal sections of uncleared leaves, the cytoplasm of these cells is very dense and stains very darkly (Fig. 22). Each crenation is supplied by an arc of vascular tissue that is derived from the union of two secondary or tertiary veins (Fig. 21).

Wood of Ixerba is diffuse porous and exhibits distinct growth rings (Fig. 23). The wood is fine-textured with very numerous angular pores (range 70-235/mm2, x= 114) that possess thin radial walls (range 1.1-3.7 um, R= 1.9) and








very small tangential diameters (range 25-55 um, R=41). The pores are predominantly solitary (76%), although radial multiples of two pores (2%) and clusters of two to five pores (22%) mostly due to overlapping end walls of vessel elements do occur. Vessel elements are long and range from 617-1600 um (R= 1149). Vessel elements possess oblique end

walls with angles ranging from 2-180 (x-= 8) and lack spiral thickenings. Perforation plates are exclusively scalariform

with 16-71 thin bars per plate (R= 40) (Fig. 24). One specimen (Aw H-20087) of Ixerba was distinct from all the others because of its exceptionally long vessel elements (range 1117-1942 um, x= 1498) and very numerous bars per scalariform perforation plate (range 47-111, R=71). Although perforations typically lack borders, perforations

with borders at the ends or rarely with complete borders may be found in the narrowest vessel elements. Intervascular pitting is extremely rare and confined to overlapping vessel element end walls. When present, round to oval pits with

small diameters (range 3.7-5.3 um, x= 4.5) typically occur in uniseriate files (Fig. 24).

Tracheids bear circular-bordered pits with oval inner

apertures that may be included within or extend beyond the margins of the pit border (Fig. 24). The diameter of these pits is similar to that of the intervascular pits. Tracheids are medium to moderately long (range 867-2084 um, X= 1438), with relatively thin radial walls (range 2.6-8.9 um, x= 4.7), and fine or coarse spiral thickenings occasionally are present.









Axial parenchyma is sparse and predominantly apotracheal diffuse and paratracheal scanty, although diffuse-inaggregates parenchyma may also occur. Vessel to axial parenchyma pitting is mostly transitional or opposite, rarely alternate. No ergastic substances are noted in these cells.

The xylem ray system predominantly is composed of homocellular, uniseriate rays of upright cells and heterocellular, bi- and multiseriate rays (Fig. 25). Most heterocellular rays are biseriate, although some may be uniseriate. Ray height ranges from 1-15 cells (.06-1.03 mm) for homocellular rays, 8-27 cells (.25-1.18 mm) for heterocellular uniseriate rays, and 6-52 cells (.25-2.00 mm) for heterocellular bi- and multiseriate rays. Heterocellular rays range from 2-4 cells (26-70 um) wide. Very few ray cells contain dark brown deposits, and crystals are absent. Sheath cells are absent, while perforated ray cells with scalariform or reticulate perforation plates commonly occur in some specimens (Fig. 26). The pitting between vessels and ray parenchyma and vessels and axial parenchyma is mostly transitional to opposite. All types of rays may be fused end-to-end.





























Figure 13. Leaf of Ixerba brexioides. Xl. Note marginal crenations and semicraspedodromous venation. Figure 14. Vein ending of I. brexioides. X175. Figure 15. Transverse sections of a node (a) and the proximal (b), median (c) and distal (d) sections of a petiole of I. brexioides.


Details: f, fibers; t, tracheids.























13 ""% ,e


15























Figure 16. Transverse section of a leaf of Ixerba brexioides. X175.

Figure 17. Optically anisotropic crystalloid from a leaf of I. brexioides. X700.

FIgure 18. Transverse section of the midvein of a leaf of I. brexioides. X110.

Figure 19. Paradermal section of the abaxial epidermis of a leaf of I. brexioides. X437. Note anomocytic stomatal apparatus.

Figure 20. Transverse section of the abaxial epidermis of a leaf of I. brexioides. X700. Note the guard cells with small cuticular horns (arrows).


Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; cr, crystalloid; gc, guard cells; lp, lignified parenchyma; pl, palisade layer; sl, spongy mesophyll layer ; st, stoma; vb, vascular bundle.


























Figure 21. Marginal crenation of a leaf of Ixerba brexioides. X110. Note the arc of vascular tissue.

Figure 22. Paradermal section of a marginal crenation of a leaf of I. brexioides. X110. Note apical gland.

Figure 23. Transverse section of the secondary xylem of I. brexioides. X110. Note solitary, angular pores.

Figure 24. Radial section of the secondary xylem of I. brexioides. X437.

Figure 25. Tangential section of the secondary xylem of I. brexioides. X110. Note uni- and biserate rays.

Figure 26. Radial section of the secondary xylem of I. brexioides. X437. Note the perforated ray cell with scalariform perforation plate.


Details: g, gland; p, pore; pc, perforated ray cell; pi, pits; pp, perforation plate; r, ray parenchyma; t, tracheid; v, vessel element; vt, vascular tissue.















Bauera Banks

Introduction

The genus Bauera was named by Sir Joseph Banks and

described from specimens of B. rubioides in 1801 (Bailey, 1900; Bentham, 1864; Black, 1924; Burbidge, 1963; Willis, 1972). The generic name commemorates the botanical artists Francis and Ferdinand Bauer (Bailey, 1900; Black, 1924). The three species of this genus are endemic to southeastern Australia and Tasmania. Bauera rubioides, the most widespread species, occurs in wet places throughout Tasmania, eastern Victoria, eastern New South Wales and southeastern Queensland (Black, 1924; Bailey, 1900; Bentham, 1864; Willis, 1972). This species is rare on Kangaroo Island in South Australia (Mosley, 1974a). Bauera capitata occurs in southeastern New South Wales and Fraser's Island off the coast of southeastern Queensland (Bailey, 1900; Bentham, 1864). Bauera sessiliflora is restricted to the Grampian Mountain range in western Victoria. Plants of Bauera are either prostrate or upright shrubs up to 2 m tall. All species of Bauera reportedly bear opposite, sessile, exstipulate, three-foliolate leaves which give the appearance of a whorl of six leaves (Bailey, 1900; Bentham, 1864). Although flowers may have four to ten sepals and petals, most flowers have five to nine sepals and petals (Bailey, 1900; Bentham, 1864; Dickison, 1975b). Each flower possesses a few to many stamens and contains a









superior to half-inferior, bicarpellate, syncarpous gynoecium that ripens into a capsule. Bauera is commonly grown as a greenhouse shrub (Bailey, 1944; Bailey and Bailey, 1976; Synge, 1974).

Although Hooker (1865) considered Bauera an anomalous genus within the Saxifragaceae, Bentham (1864) placed it in the tribe Cunonieae of the Saxifragaceae. Two recent workers (Cronquist, 1981; Takhtajan, 1980, 1983) have placed this genus in the Cunoniaceae, and have aligned this family within either the order Grossulariales or Saxifragales, respectively. Other systematists have placed Bauera in the monogeneric subfamily Baueroideae of the Saxifragaceae (Engler, 1890, 1928; Schulze-Menz 1964; Thorne, 1976), and included this family in the Rosales. Thorne (1983), however, recently has placed this genus in the monogeneric family Baueraceae, as have other workers (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Hutchinson, 1967), and they all place the Baueraceae among the Cunoniales.

Wood, nodes and leaves of B. rubioides and B.

sessiliflora, and nodes and leaves of B. capitata were available for study (Table 2). Unless noted otherwise, data apply to all species examined. Observations

Bauera typically possesses simple, opposite, petiolate leaves, although B. rubioides may have whorled leaves. Each leaf is accompanied laterally by two large stipules that are









morphologically and anatomically similar to the leaves. Each stipule is attached to the stem by a very short stalk. Leaves of B. rubioides and B. sessiliflora are elliptic or ovate with entire to obscurely toothed margins (Fig. 27). Leaves of B. capitata may be elliptic or two- to three-lobed (Fig. 28). Venation is semicraspedodromous to brochidodromous in B. rubioides and B. sessiliflora with a prominent midvein and conspicuous secondary veins that either extend to the leaf margin and/or form arches with superadjacent secondary veins (Fig. 27). Venation is mixed craspedodromous in B. capitata with some secondary veins that extend to the leaf margin and others that arch distally to join with superadjacent secondary veins (Fig. 28). Vein areole development is incomplete in B. sessiliflora and lacking in both B. rubioides and B. capitata. Veinlets typically are forked or branched. Most tracheids of a vein ending are elongate and slender with helical thickenings, while the terminal tracheids of a vein ending usually are shorter, larger in diameter and thicker-walled than the elongate tracheids (Fig. 29). The terminal tracheids have reticulate wall thickenings and may possess short protuberances.

The nodal pattern is unilacunar, one-trace, and this leaf trace quickly splits twice to form three traces, each of which is a collateral bundle (Fig. 30). The median trace enters a leaf, and each of the lateral traces enters a lateral, foliaceous stipule. These bundles traverse the length of a short petiole or stipular stalk (Fig. 30). At








approximately the same level as the trifurcation of the leaf trace in the stem, two branch traces arise and quickly fuse to form a cylindrical stele in the branch opposite a simple leaf (Fig. 30).

Leaves of Bauera are dorsiventral with a welldifferentiated, uni- to biseriate palisade layer and a highly lacunose spongy mesophyll layer (Fig. 31). The palisade cells typically are elongate and columnar, but may be short and oval in transection. These cells may be tightly appressed or loosely arranged with small intercellular spaces. The cells of the spongy mesophyll have various shapes and sizes and are separated by numerous, large intercellular spaces. Prismatic crystals are common in the spongy mesophyll cells, especially near a vascular bundle (Fig. 32).

The oval or round vascular bundles of Bauera leaves are collateral, and only the midvein exhibits a small amount of secondary growth. Although bundle sheaths and bundle sheath extensions are absent, thick-walled fibers commonly occur adjacent to the primary vascular tissues of each bundle (Fig. 31).

The abaxial epidermis in all species is exclusively

uniseriate and composed of very narrow, thick-walled cells in transection. The adaxial epidermis is uniseriate (B. capitata and B. rubioides) or biseriate (B. rubioides and B. sessiliflora). In the latter species the cells of the outermost layer of the adaxial epidermis resemble those of the abaxial epidermis, while the cells of the innermost layer are composed of very large, thin-walled cells









(Fig. 33). These latter cells are very delicate and often become distorted and disintegrate when sectioned (Fig. 34). In surface view the cells of both the abaxial epidermis and the outermost layer of the adaxial epidermis are variously shaped and possess sinuous or curved anticlinal walls. Although the cuticle is thin (<5 um) in all three species, it is slightly thicker on the abaxial surface of a leaf.

Numerous stomata are restricted to the abaxial epidermis. The stomatal apparatus is anomocytic, although the three or four subsidary cells which surround a guard-cell pair are smaller than the other epidermal cells (Fig. 35). In surface view individual guard cells are reniform, and guard-cell pairs are elliptic to circular in outline (Fig. 35). Guard-cell-pair length averages 32 um and width averages 29 um (length/width ratio 1.10). In transection guard cells are oval, and each cell bears a large cuticular horn that represents the outer ledge overarching a stoma (Fig. 36). Unicellular, thick-walled, lignified trichomes with tapered ends are abundant on both epidermal layers and along the margins of leaves of B. rubioides and B. sessiliflora, but are sparse on the leaves of B. capitata (Fig. 37). The base of each trichome is surrounded by a ring of epidermal cells which are much larger than the surrounding epidermal cells (Figs. 33 & 34). One or two adaxial epidermal cells along most of the margin of the leaves of B. capitata are expanded into a ridge which appears as an elongate or clavate protrusion in transection (Fig. 38).









The apex and marginal teeth of a leaf possess thickwalled cells with darkly staining cytoplasm that resemble glandular cells (Fig. 37).

Although the wood of the two species of Bauera studied is very similar, B. sessiliflora has longer vessel elements and tracheids and taller rays than B. rubioides. Distinct growth layers occur in the wood of both species. The wood of B. rubioides is diffuse porous while the wood of B. sessiliflora is ring porous (Fig. 39). Both species possess very numerous pores, with ranges of 270-385/mm2 (R= 325) for B. rubioides and 185-320/mm2 (x= 257) for B. sessiliflora. Both species have thin-walled (range 1.1-4.2 um, x= 2.0) angular pores with very small tangential diameters (range 18-57 um, R= 37). Pores are predominantly solitary (84%), although true radial multiples (3%) and clusters (13%) do occur. Vessel elements are medium length, however, those of B. sessiliflora (range 234-780 um, R= 523) are longer than those of B. rubioides (range 208-579 um, x= 383). Vessel element end walls vary from transverse to oblique, with end-wall angles that range from 22-900 (x= 39). Perforation plates are typically simple, however scalariform perforation plates with 1-5 thin bars may occur in both species (Fig. 40). All perforations lack borders. Very fine spiral thickenings rarely occur in the vessel elements of B. sessiliflora only. Intervascular pitting usually is scalariform or transitional in both species, although opposite or alternate patterns rarely occur








(Fig. 40). The diameter of the elongate or oval pits is minute (range 3.2-7.4 um, x= 4.7).

Tracheids of both species bear circular-bordered pits with oval inner apertures that are included within the pit border (Fig. 41). The diameter of these pits is similar to that of the intervascular pits. The tracheids of both species are very short, although those of B. sessiliflora are longer (range 436-956 um, x= 721) than those of B. rubioides (range 312-650 um, x= 484). These tracheids have relatively thin radial walls (range 2.6-5.3 um, x= 3.7) and fine spiral thickenings.

Axial parenchyma is sparse and either apotracheal diffuse or paratracheal scanty. Vessel to axial parenchyma pitting is not visible in the material examined. Dark brown deposits commonly occur in these cells.

The xylem ray system is composed mostly of homocellular, uniseriate rays of upright or square cells and a few heterocellular, bi- and multiseriate rays (Fig. 42). Homocellular, biseriate and heterocellular, uniseriate rays are rare. The homocellular rays are slightly taller in B. sessiliflora (1-14 cells, 0.11-0.81 mm) than in B. rubioides (1-6 cells, 0.04-0.31 mm). Although heterocellular rays also are taller in B. sessiliflora (18-84 cells, 0.50-1.89 mm) than in B. rubioides (19-61 cells, 0.32-0.98 mm), the

width of these rays is similar in both species (2-7 cells, 18-75 urn). Dark brown deposits commonly occur in the ray cells of both species (Fig. 40). Sheath cells are absent, while perforated ray cells with simple or foraminate





50



perforation plates are occasionally present (Fig. 41). Vessel to ray parenchyma pitting is scalariform to fenestriform. Both homocellular and heterocellular rays may be fused end-to-end.































Figure 27. Leaf of Bauera rubioides. X10. Note semicraspedodromous to brochidodromous venation. Figure 28. Diversity of leaf shapes in B. capitata. X10. Figure 29. Vein ending of B. rubioides. X437. Note helically thickened tracheids.


Details: t, tracheids.





27 28



ow
t







29---




























Figure 30. Diagrammatic representation of a node and the nodal pattern of Bauera rubioides. X30. Leaves and stipules are not drawn to scale.


Details: stipule;


BT, branch trace; L, leaf; LT, leaf trace; S, ST, stipular traces.


























co



































cn

cl



















Figure 31. Transverse section of a leaf of Bauera capitata. X175.

Figure 32. Transverse section of a leaf of B. capitata showing prismatic crystals near a vascular bundle. X700.

Figure 33. Transverse section of a leaf of B. sessiliflora. X110.

Figure 34. Transverse section of a leaf of B. sessiliflora. X110.

Figure 35. Paradermal section of the abaxial epidermis of a leaf of B. rubioides. X437. Note anomocytic stomatal apparatus.

Figure 36. Transverse section of the abaxial epidermis of a leaf of B. capitata. X700. Note the guard cells with prominent cuticular horns (arrows).

Figure 37. Marginal serration of a leaf of B. rubioides. X175. Note marginal trichome.

Figure 38. Transverse section of a leaf of B. capitata. X175. Note the protrusion (arrow) that represents a ridge of cells along the adaxial margin of a leaf.


Details: ab, abaxial epidermis; ad, adaxial epidermis; c, cuticle; cr, crystal; e, enlarged epidermal cells; f, fibers; g, gland; gc, guard cells; m, midvein;; pl, palisade layer; sl, spongy mesophyll layer; st, stoma; tr, trichome.















ad ad



e


t 1-4


33


34-

























Figure 39. Transverse section of the secondary xylem of Bauera rubioides. X110. Note boundary of growth ring (arrow) and solitary, angular pores.


Figure 40. rubioides.


Radial section of the secondary xylem of B. X175.


Figure 41. Radial section of the secondary xylem of B. sessiliflora. X437. Note tracheids with circular-bord-ered pits and perforated ray cell with a simple perforation plate.

Figure 42. Tangential section of the secondary xylem of B. sessiliflora. X110. Note uni-, bi- and multiseriate rays.


Details: p, pore; perforation plate; element;


pc, perforated ray cell; pi, pits; pp, r, ray; t, tracheid; v, vessel















Anopterus Labill.


Introduction

Anopterus was described from specimens of A. glandulosus by J.-J. Labillardiere in 1804. The generic name refers to the broad, membranaceous wing on the end of each seed produced by these plants (Bailey, 1900). The type species is endemic to Tasmania where it is widespread throughout the island, especially in subalpine forests (Bentham, 1864; Mosely, 1974b). The only other species in the genus, A. macleayanus, is endemic to eastern and southeastern Queensland and northeastern New South Wales, Australia where it occurs up to elevations of 1500 m (Bailey, 1900; Bentham, 1864; Burbidge, 1963). Plants within the genus are shrubs or small trees with alternate, simple, exstipulate leaves (Bailey, 1900; Bentham, 1864). The sixto nine-merous flowers are borne in racemes, and each contains a bicarpellate, superior ovary that ripens into a capsule. Anopterus glandulosus commonly is used in ornamental horticulture for its handsome evergreen foliage (Bailey 1944; Bailey and Bailey, 1976; Synge, 1974).

Most taxonomists have placed Anopterus in either the Saxifragaceae, subfamily Escallonioideae (Engler, 1890, 1928; Schulze-Menz 1964; Thorne, 1976, 1983) or the Escalloniaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1980, 1983). Cronquist (1981), however,








included this genus in his Grossulariaceae. Although most of these systematists have included these taxa in the Rosales or some roughly equivalent order, some workers have placed them in either the Cunoniales (Hutchinson, 1967) or the Cornales (Dahlgren, 1975, 1980, 1983).

Wood, leaves, and nodes of A. glandulosus and A.

macleayanus were examined in this study (Table 2). Unless noted otherwise, data apply to both species.


Observations

Anopterus macleayanus possesses very long, narrowly oblanceolate to oblanceolate leaves while A. glandulosus possesses smaller, oblanceolate leaves. The leaves of both species bear blunt crenations (Fig. 43). Venation is semicraspedodromous with a prominent midvein and conspicuous secondary veins whose branches extend near the leaf margin and arch distally to join with superadjacent secondary or tertiary veins (Fig. 43). Vein areoles are smaller and their development is imperfect in A. macleayanus, while they are larger and their development is incomplete in A. glandulosus. Veinlets vary from straight to once or twice branched. Vein endings are usually tapered and simple, but may be clavate or branched. These vein endings are composed of two to eight helically thickened tracheids that usually are elongate but, may have irregular shapes (Fig. 44). Some tracheids possess small protuberances on their side walls that are characterized by helical thickenings that differ in orientation from the thickenings in the remainder of the








cell. These protuberances are less common in A. macleayanus than in A. glandulosus. In the latter species they often correspond to the interface between two large, irregularly shaped bundle sheath cells. Bundle sheath cells are not visible in the vein endings of A. macleayanus.

Although the nodal pattern is trilacunar, three-trace in Anopterus (Fig. 45), the vasculature of the petiole is very different for the two species (Figs. 46 & 47). In A. glandulosus, three collateral bundles enter the base of a petiole, traverse its entire length and enter the lamina distally (Fig. 46). Three bundles also enter the base of a petiole in A. macleayanus (Fig. 47). However, only the middle bundle is collateral, while the two lateral bundles are amphicribral (Fig. 47). Near the base of a petiole in A. macleayanus, the middle, collateral bundle enlarges to form a horseshoe-shaped or concentric central bundle with the two lateral, amphicribral bundles on either side. In the proximal half of a petiole two large gaps form in the large central bundle opposite the lateral amphicribral bundles. The central bundle also may divide at positions other than opposite the lateral bundles. Near a median point on a petiole the two amphicribral bundles become collateral and arc-shaped with xylem internal, and each of these bundles fuses with the dissected central bundle (Fig. 47). All of the remaining bundles of the dissected central bundle fuse to form a large horseshoe-shaped bundle that enters the lamina distally (Fig. 47).








Leaves of Anopterus are dorsiventral with a narrow,

typically uniseriate, rarely biseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 48). The uppermost cells of the palisade layer are elongate and tightly appressed while the lowermost cells are shorter and more loosely arranged. These latter cells are typically intermingled with the spongy mesophyll cells. The elongate uppermost palisade cells of A. glandulosus are somewhat longer than those of A. macleayanus. The spongy mesophyll cells have various shapes and sizes and are separated by large intercellular spaces. Druses are common in the spongy mesophyll cells of A. macleayanus, but infrequently occur in A. glandulosus.

The vascular bundles of a leaf typically are collateral, however, certain bundles (secondary veins) in A. macleayanus are amphicribral. The midvein and larger bundles (secondary veins) of both species exhibit a moderate amount of secondary growth. The midvein of A. glandulosus is relatively small and flattened or arc-shaped (Fig. 49), whereas that of A. macleayanus is very large and horseshoeshaped (Fig. 50). In A. glandulosus the midvein is surrounded by thick-walled, lignified parenchyma cells adaxially and thin-walled parenchyma cells abaxially. Bundle sheath extensions of large diameter, thick-walled, unlignified parenchyma cells occur abaxially and adaxially. The larger bundles in this species have thick-walled fibers adjacent to the primary phloem, and all vascular bundles, except the midvein, are surrounded by parenchymatous bundle








sheaths without bundle sheath extensions. In A. macleayanus thick-walled fibers occur adjacent to the primary phloem of the large midvein and the amphicribral bundles (secondary veins) (Fig. 50). The ground tissue adjacent to the primary xylem and abaxial to the midvein consists of large diameter parenchyma cells (Fig. 50). Smaller, thicker-walled, unlignified parenchyma cells occur adaxially to these large diameter parenchyma cells. The smaller bundles (minor veins) in A. macleayanus lack bundle sheaths and extensions.

Both epidermal layers are uniseriate, and their cells have various shapes in transection (Fig. 48). The cell walls of the epidermal cells are slightly thicker than those of the mesophyll cells. In surface view epidermal cells are variously shaped and generally possess sinuous anticlinal walls, although the abaxial epidermal cells of A. qlandulosus may have curved anticlinal walls. The cuticle is thin (<5 um) and trichomes are absent.

Numerous stomata are restricted to the abaxial epidermis, and the stomatal apparatus is anomocytic. In surface view guard cells are reniform and guard-cell pairs are virtually circular in outline. Guard-cell pairs have an average length of 36 um and a width of 34.5 um (length/width ratio 1.04) in A. glandulosus, while those of A. macleayanus have an average length of 31 um and a width of 33 um (length/width ratio .94). In transection guard cells are oval and thick-walled, and each cell bears a short, curved cuticular horn that represents the outer ledge overarching the stoma (Fig. 51).









The apex and marginal crenations of Anopterus leaves contain glands at their apices. In leaf clearings these glands are characterized by dark-staining, thick-walled parenchyma cells arranged in regular files (Fig. 52). In paradermal sections of uncleared leaves, the cytoplasm of these cells is very dense and stains very darkly (Fig. 53). Each marginal crenation is supplied by an arc of vascular tissue that is derived from the union of two or more secondary or tertiary veins (Fig. 52).

The wood of Anopterus exhibits distinct growth rings (Fig. 54). The wood of A. macleayanus is exclusively diffuse porous. While wood of A. glandulosus is mostly semiring porous, it also may be diffuse porous. Anopterus wood is fine-textured with very numerous angular pores (range 60210/mm2, R= 128) that possess very small tangential diameters. Pores of A. glandulosus are narrower (range 25-47 um, x= 37) than those of A. macleayanus (range 26-68 um, x= 48). In both species pore distribution is mostly solitary (78%), although radial multiples of two to three cells (2%) and clusters of two to five cells (20%), mostly due to overlapping end walls of vessel elements, do occur (Fig. 54). The vessel elements of both species have very thin radial walls (range 1.1-3.7 um, R= 2.4) and lack spiral thickenings. These cells are long in both species, although they are longer in A. macleayanus (range 667-2084 um, x_= 1220) than in A. glandulosus (range 483-1634 um, x= 1023). Vessel elements possess oblique end walls with angles that range








from 3-210 (x= 10). Perforation plates are exclusively scalariform with 7-44 bars per plate (x= 24) (Fig. 55). Bars are thin and often forked or branched. Occasionally two scalariform perforation plates occur per oblique vessel element end wall. Perforations commonly lack a border, however, in the narrowest vessel elements they may be bordered at the ends or completely bordered. Only one specimen of A. glandulosus (F. M. Hueber 3/17/70) possesses a few thin-walled tyloses in some vessels and trabeculae in some vessels and tracheids. This specimen also is the only one with abundant fungal hyphae throughout the wood. Intervascular pitting is uncommon in Anopterus, but, when present, these pits are very irregular and confined to overlapping end walls (Fig. 55). Intervascular pitting may be scalariform, transitional, opposite, or alternate, although transitional and opposite are the most common patterns. These elongate or oval pits have minute to small diameters (range

3.2-7.4 um, x= 5.0).

Tracheids bear circular-bordered pits with oval to

slit-like inner apertures that may be included within or extend beyond the margins of the pit border. The diameter of these pits is similar to that of the intervascular pits. Tracheids are medium to moderately long, and these cells in A. macleayanus are slightly longer (range 984-2134 um, x 1465) than those in A. glandulosus (range 1000-1734 um, x 1315). These tracheary elements have relatively thick radial walls (range 3.2-7.4 um, x= 5.2) and fine spiral thickenings (Fig. 55).









Axial parenchyma is sparse and predominantly apotracheal diffuse, although a few cells may be paratracheal scanty, or apotracheal marginal at the beginning of a growth layer. Vessel to axial parenchyma pitting, although rarely seen, is transitional, opposite, or alternate. No ergastic substances are noted in these cells.

The xylem ray system is composed of homocellular, uniseriate rays of upright cells and heterocellular, bi- and multiseriate rays (Fig. 56). One very young specimen of A. macleayanus has a few heterocellular, uniseriate rays. Homocellular rays are 1-20 cells high (.10-2.83 mm) for both species of Anopterus. Heterocellular rays are taller in A. glandulosus (7-53 cells, .37-3.97 mm) than in A. macleayanus (height: 7-37 cells, .33-2.63 mm). Heterocellular rays are also a bit wider in A. glandulosus (2-10 cells, 31-187 um) than in A. macleayanus (2-3 cells, 44-62 um). These differences in width are relatively minor because most heterocellular rays are 2-4 cells wide in both species. Dark brown deposits and starch grains are present in some ray cells. Sheath cells are absent, while perforated ray cells with scalariform perforation plates are occasionally present in both species (Fig. 57). Vessel to ray parenchyma pitting is transitional to mostly opposite, or alternate. All types of

rays may be fused end-to-end, and all types may be split by vessels and/or tracheids.




























Figure 43. Leaf of Anopterus glandulosus. Xl. Note marginal crenations and semicraspedodromous venation.

Figure 44. Vein ending of A. glandulosus. X175.

Figure 45. Transverse section of a node of A. glandulosus. X10.

Figure 46. Transverse sections of proximal (a), median (b) and distal (c) sections of a petiole of A. glandulosus. X10.

Figure 47. Transverse sections of proximal (a), median
(b) and distal (c) sections of a petiole of A. macleayanus. X10.


Details: t, tracheids.


I




















45





a b c

,/,46 47


43


41
#


44




















Figure 48. Transverse section of a leaf of Anopterus glandulosus. X110.

Figure 49. Transverse section of the midvein of a leaf of A. glandulosus. X46.

Figure 50. Transverse section of the midvein of a leaf of A. macleayanus. X46. Note secondary vein.

Figure 51. Transverse section of the abaxial epidermis of a leaf of A. glandulosus. X700. Note guard cells with small cuticular horns (arrows).

Figure 52. Marginal crenation of a leaf of A. glandulosus. X110. Note the arc of vascular tissue which vascularizes the crenation.

Figure 53. Paradermal section of a marginal crenation of a leaf of A. glandulosus. X110.


Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundel sheath extension; be', adaxial bundle sheath extension; c, cuticle; f, fiber; g, gland; gc, guard cells; gt, ground tissue; pl, palisade layer; sl, spongy mesophyll layer; sv, secondary vein; vb, vascular bundle; vt, vascular tissue.






























Figure 54. Transverse section of the secondary xylem of Anopterus glandulosus. X110. Note boundary of growth ring (arrow) and solitary, angular pores.

Figure 55. Radial section of the secondary xylem of A. glandulosus. X437. Note spiral thickenings (arrow) in tracheids.

Figure 56. Tangential section of the secondary xylem of A. glandulosus. Xll0. Note uni-, bi- and multiseriate rays.

Figure 57. Radial section of the secondary xylem of A. glandulosus. X437. Note perforated ray cell with scalariform perforation plate. X437.


Details: p, pore; pc, perforated ray cell; pi, pits; pp, perforation plate; r, ray; t, tracheid;





mug---- -


(A


r 7 A!'!p , - - I - -'- At I

-


Nr












Cuttsia F. v. Muell.

Introduction

The monotypic genus Cuttsia was described by Ferdinand von Mueller in 1865 from specimens of C. viburnea. The generic name commemorates J. Cutts, the treasurer of the "Ladies Leichhardt Search Expedition," a group of women who raised money to support a search expedition to account for the disapperance of Ludwig Leichhardt (Mueller, 1865; Willis, 1949). This genus is endemic to southeastern Queensland and northeastern New South Wales, Australia and occurs along mountain streams (Bailey, 1900; Burbridge, 1963). Cuttsia viburnea is a shrub or small tree bearing exstipulate, simple, alternate leaves. The five-merous flowers are arranged in panicules, and each possesses a superior ovary that ripens into a capsule (Bailey, 1900; Engler, 1928).

Most systematists agree that Cuttsia belongs in either the subfamily Escallonioideae of the Saxifragaceae (Engler, 1890, 1928; Schulze-Menz, 1964; Thorne, 1976, 1983) or the Escalloniaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966, 1980). Cronquist (1968, 1981), however, placed this genus in his Grossulariaceae.


Observations

Cuttsia possesses simple, elliptic to ovate, serrate leaves. Venation is semicraspedodromous with a prominent









midvein and conspicuous secondary veins whose branches extend near the leaf margin and arch distally to join with superadjacent secondary or tertiary veins (Fig. 58). Areole development is incomplete. Veinlets may be straight, curved, or branched one to three times (Fig. 59). Vein endings are composed of two to five helically thickened tracheids that are surrounded by large-diameter parenchyma cells of the bundle sheath. These tracheids are usually elongate and possess very small protuberances whose position corresponds to the interface between two bundle sheath cells (Fig. 59).

The nodal pattern is trilacunar, three-trace, and three collateral bundles enter a petiole (Fig. 60). Near the base of a petiole a very small accessory vascular bundle branches from each of the lateral bundles near the adaxial surface of the petiole (Fig. 60). Distally from the point of divergence of these accessory bundles, the three main petiolar bundles fuse laterally to form a large horseshoe-shaped vascular bundle in the center of the petiole (Fig. 60). Two bundles may split from the adaxial side of this large central bundle (Fig. 60) or, in some petioles, the ends of the large central bundle may invaginate or become inrolled. In some petioles these inrolled ends may fuse to form a large, medullated concentric bundle with the xylem internal to the phloem. Distally each of the accessory bundles near the adaxial surface of a petiole splits to form two additional accessory bundles (Fig. 60).








Leaves of Cuttsia are dorsiventral with a welldifferentiated biseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 61). The palisade cells adjacent to the spongy mesophyll are widely spaced and exhibit various shapes and sizes compared to the columnar and closely appressed cells of the remainder of the palisade layer (Fig. 61). The spongy mesophyll is approximately the same thickness as the palisade layer and is composed of cells of various shapes and sizes and relatively large intercellular spaces. Crystal sand occurs sporadically in the larger cells of the spongy mesophyll (Fig. 62). In addition small clusters of yellowish cells are visible throughout the mesophyll of cleared leaves (Fig. 59).

The midvein of Cuttsia leaves may be arc-shaped,

horseshoe-shaped with either collateral bundles or inrolled ends at the top of the horseshoe, or concentric and medullated (Fig. 63). Secondary growth is well-developed in the midvein and larger bundles (secondary veins). A large bundle sheath of thin-walled parenchyma cells surrounds each vascular bundle of a leaf (Fig. 61). Abaxial and adaxial bundle sheath extensions are associated with most bundles except for the very small veins. These bundle sheath extensions are composed of thick-walled parenchyma and collenchyma cells.

The adaxial epidermis is biseriate, whereas the abaxial epidermis is uniseriate (Fig. 61). In transection the cells of the abaxial epidermis and the outermost cells of the adaxial epidermis are rectangular to oval in outline. The








subjacent cells of the adaxial epidermis are square, round, oval, or rectangular (Fig. 61). In surface view the cells of the abaxial epidermis and the outermost cells of the adaxial epidermis are variously shaped and possess curved and sinuous anticlinal walls. The cuticle overlying both epidermides is very thin (<5 um). Unicellular, elongate, bulbous-based, thick-walled trichomes with tapered ends generally are sparse on abaxial leaf surfaces, but are common along the large veins.

Numerous stomata occur mostly in the abaxial epidermis, but also occur in the adaxial epidermis in association with hydathodes. The stomatal apparatus is anomocytic. In surface view individual guard cells are reniform, and guardcell pairs are elliptic in outline (Fig. 64). Guard-cell pairs average 29 um in length and 21.3 um in width (length/ width ratio 1.36). In transection the guard cells are galeate in outline, and each cell bears a small cuticular horn that represents the outer ledge overarching the stoma.

The apex and marginal teeth of a leaf of Cuttsia contain hydathodes. A prominent vein flares as it enters each marginal tooth (Fig. 65). In leaf clearings, a callosity composed of thick-walled cells is visible at the apex of the rounded marginal serrations. These thick-walled cells stain

more darkly than other cells of a tooth (Fig. 65).

The wood of C. viburnea lacks growth rings (Fig. 66)

and is fine-textured with numerous pores (range 10 -75/mm2, R= 37) that possess moderately small diameters (range 39-88 um, R= 64) and relatively thin radial walls (range 1.6-6.3








urn, x= 3.5). Pores are predominantly solitary (87%), although radial multiples of two pores (1%) and clusters of two to four pores (12%) mostly due to overlapping end walls of contiguous vessel elements do occur. The pores primarily are angular in outline, however some may appear circular because their corners are often rounded (Fig. 66). The vessel elements are long (range 817 to 2367 um, x= 1368) and possess steeply inclined oblique end walls. End-wall angles range from 6-300 (x= 15). Peforation plates are exclusively scalariform and possess 32-104 bars per plate (x= 57) (Fig. 67). occasionally two scalariform perforation plates occur per oblique vessel element end wall. Scalariform perforation plate bars are thin and may be forked or branched. Perforations are bordered at the ends. Transitional, opposite to alternate intervascular pitting is confined to overlapping end walls, and the pits often intergrade with the scalariform perforation plates (Fig. 67). Pits are small in diameter and range from 3.2-5.8 um (R= 4.6).

Tracheids have circular bordered pits with oval apertures that may be included within or extend beyond the margins of the pit border (Fig. 67). The diameter of these pits is similar to that of the intervascular pits. These cells are very long (range 1517-3267 um, x= 2396 um). Tracheid wall thickness varies from 3.7 to 13.7 um (R= 7.5 um). Fine spiral thickenings are present in most of these tracheary elements (Fig. 67).

Axial parenchyma is sparse and mostly apotracheal diffuse or diffuse-in-aggregates with short tangential bands









of two to four cells (Fig. 66). Rarely xylem parenchyma is paratracheal scanty. Vessel to axial parenchyma pitting is transitional, opposite or alternate. No ergastic substances are noted in these cells.

Although the xylem ray system is predominantly composed of homocellular, uniseriate rays of upright cells and heterocellular, multiseriate rays (Fig. 68), a few homocellular, biseriate rays of upright cells are present in each specimen. Ray height ranges from 2-27 cells (1.33-3.23 mm) for uniseriate rays, 4-30 cells (.65-3.92 mm) for biseriate rays, and 24-251 cells (1.40-11.37 mm) for multiseriate rays. Biseriate rays are 10-13 um wide, and multiseriate rays mostly are 3-9 cells (34-163 um) wide. One specimen (FPAw 18202) had rays up to 20 cells (650 um) wide. No ergastic substances are noted in these cells. Sheath cells completely surround the multiseriate rays (Fig. 68), and perforated ray cells with scalariform or reticulate perforation plates are commonly found in the uniseriate tails of multiseriate rays (Fig. 69). Vessel to ray parenchyma pitting is similar to pitting between vessels and axial parenchyma and is scalariform, transitional, opposite, or alternate. Multiseriate rays often are split by tracheids and/or vessels, and occasionally multiseriate rays are fused endto-end.





























Figure 58. Leaf of Cuttsia viburnea. Xl/2. Note marginal serrations and semicraspedodromous venation.

Figure 59. Vein ending of C. viburnea X175. Note small clusters of cells in the mesophyll.

Figure 60. Transverse sections of a node (a) and proximal
(b), median (c) and distal (d) sections of a petiole of C. viburnea. X13.


Details: cc, cluster of cells; t, tracheids.





58


6 -


le t


,cc


i6


60























Figure 61. Transverse section of a leaf of Cuttsia viburnea. X175. Note biseriate adaxial epidermis.

Figure 62. Crystal sand (arrows) in the spongy mesophyll layer of a leaf of C. viburnea. X700.

Figure 63. Transverse section of a midvein of a leaf of C. viburnea. X110. Note the constricted nature of the adaxial bundle sheath extension.

Figure 64. Paradermal section of the abaxial epidermis of a leaf of C. viburnea. X700. Note anomocytic stomatal apparatus.

Figure 65. Marginal serration of a leaf of C. viburnea. X110. Note the prominent flaring of vein and the apical callosity.


Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; ca, callosity; gc, guard cell; pl, palisade layer; sl, spongy mesophyll layer ; st, stoma; vb, vascular bundle; v, vein.




























Figure 66. Transverse section of the secondary xylem of Cuttsia viburnea. Xll0. Note solitary, angular pores and diffuse and diffuse-in-aggregates axial parenchyma.

Figure 67. Radial section of the secondary xylem of C. viburnea. X437. Note fine spiral thickenings (arrow).

Figure 68. Tangential section of the secondary xylem of C. viburnea. Xl0. Note sheath cells.

Figure 69. Radial section of the secondary xylem of C. viburnea. X175. Note perforated ray cell with a scalariform perforation plate. X175.


Details: ap, axial parenchyma; p, pore; pc, perforated ray cell; pi, pits; pp, perforation plate; r, ray; sc, sheath cell; t, tracheid.







Full Text

PAGE 1

COMPARATIVE ANATOMY AND SYSTEMATICS OF TWELVE WOODY AUSTRALASIAN GENERA OF THE SAXIFRAGACEAE By MATTHEW HENRY HILS A DISSERTATION PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMEN'l ' OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1985

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1 --ACKNOWLEDGEMENTS I thank the members of my committee, Drs. Lucansky, Perl, Huffman, Judd and Stern for their guidance and pa tience in helping me complete this dissertation. I am especially grateful to Dr. Lucansky for his extensive help in organizing and criticizing this dissertation, and Dr. Stern for posing the research problem and providing the samples and materials with which to work. Special thanks go to Dr. Nordlie for his eleventh hour efforts. My thanks also go to the rest of the faculty and graduate students of the Department of Botany for the many questions they an swered and their encouragement. I express gratitude to my colleagues, friends and students at Hiram College who have been very supportive during the past year. Robert Sawyer and Robert Kiger provided help with translation of a Latin description, and Wes Tree assisted with the photographs. I am very grateful to John W. Thieret, friend and colleague, for his counsel and assistance over the past six years. I also am very fortunate to have the full support of my family in my work; I owe them more than I could ever repay. Last ly, I dedicate this work to my wife, Wendy E. Mahon-Hils, who has provided the illustrations within, but more impor tantly, has given me more love and understanding than I could ever hope for in married life. Kithout her, this work could not have been completed. ii

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TABLE OF CONTENTS SECTION PAGE ACKNOWLEDGEMENTS ........................................ ii LIST OF TABLES ........................................... V LI ST OF FIGURES ......................................... vi KEY TO TISSUES: NODES AND PETIOLES ....... ............. xiv ABSTRACT ................................................ xv INTRODUCTION ............................................. 1 Systematics of the Saxifragaceae .................... 1 Anatomical Work on the Saxifragaceae ................ 3 Anatomical Work on New Zealand Genera ............... 6 Anatomical Work on the Cunoniaceae .................. 9 Rationale for the Present Study .................... 10 MATERIALS AND METHODS ................................... 14 RESULTS . ................................................ 19 Tetracarpaea Hook. . ............................... 19 Ixerba A. Cunn. . .................................. 31 Bauera Banks ...................................... 43 Anopterus Labill .................................. 59 Cutts i a F . v . Mue 11 . . ............................. 7 3 Abrophyllum Hook. f .•....•....•..........•...•..•. 85 Carpodetus J. R. & G. Forst ....................... 95 Corokia A. Cunn . ................................ . 110 Argophyllum J. R. & G. Forst ..................... 127 Donatia J. R. & G. Forst ......................... 141 Anodopetalum A. Cunn ............................. 150 Aphanopeta 1 um End 1 . . .....................•.•.•... 16 0 DISCUSSION ............................................. 168 Anatomy of Twelve Australasian Genera ............. 168 Relationships of Ixerba .................•......... 173 Relationships of Anopterus ........................ 176 Relationships of Cuttsia and Abrophyllum .......... 179 Relationships of Carpodetus ....................... 181 Relationships of Corokia and Argophyllum .......... 185 Relationships Among the Escallonioideae ........... 190 iii

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Possible Delimitation of the Escallonioideae ...... 193 Relationships of Tetracarpaea ..................... 195 Relationships of Bauera ........................... 198 Re 1 a tionships of Anodopeta 1 um 2 0 2 Rel at ions hips of Aphanopeta 1 um 2 04 Relationships of Donatia .......................... 206 Australasian Genera and Geological History ........ 209 CONCLUSIONS 211 SU Mlv1.AR Y 2 2 0 APPENDIX . ...................................•.......... 2 21 LITERATURE CITED ....................................... 229 BIOGRAPHICAL SKETCH ....•............................... 240 iv

PAGE 5

LIST OF TABLES TABLE PAGE Table 1. Twelve Australasian g e nera classified according to Adolph Engler ........................ . ...•............. 13 Table 2. Woody saxifragaceous species from Australasia examined anatomically ..................................... 18 Table 3. Anatomical features of eleven Australasian woody saxifragaceous genera .............................. 169 Table 4. Specimens of Australasian woody Saxifragaceae examined anatomically .................................... 222 V

PAGE 6

LIST OF FIGURES FIGURE PAGE Figure 1. Leaf of Tetracarpaea tasmannica ............... 26 Figure 2. Vein ending of.'.!'...:._ tasmannica .................. 26 Figure 3. Transverse sections of a node and petiole of T. tasmannica ......................................... 26 Figure 4. Transverse section of a leaf of T. tasmanni ca ............................................... 2 8 Figure 5. Transverse section of the abaxial epidermis of a leaf of T. tasmannica ............................... 28 Figure 6. Transverse section of a leaf of T. tasmanni ca . ................................ :--: . ........... 2 8 Figure 7. Marginal tooth of a leaf of'.!:...!._ tasmannica ..... 28 Figure 8. Transverse section of the secondary xylem of T. tasmannica . ........................................... 3 0 Figure 9. Radial section of the secondary xylem of'.!:.!_ ta smanni ca ................................•.............. 3 0 Figure 10. Secondary xylem of T. tasmannica ............. 30 Figure 11. Tangential section of the secondary xylem of T ta s man n i ca . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 0 Figure 12. Radial section of the secondary xylem of T. ta sman ni ca ........................................... :--: . . 3 0 Figure 13. Leaf of Ixerba brexioides .................... 38 Figure 14. Vein ending of I. brexioides ................. 3 8 Figure 15. Transverse sections of a node and petiole of I. brexioides ......................................... 3 8 Figure 16. Transverse section of a leaf of!_:_ brexioides ............................................... 4 0 Figure 17. Optically anisotropic crystalloid from a leaf of I. brexioides ......................................... 40 vi

PAGE 7

r I Figure 18. Trans v ers e s e ct i on o f th e rn id v ein of a leaf of brexioides ............................ ............. 40 Figure 19. Paradermal s e ction of the abaxial epidermis of a leaf of I. brexioides ............................... 40 Figure 20. Transverse section of the abaxial e p idermis of a 1 ea f of I. brexioides ............................... 4 0 Figure 21. Marginal crenation of a l e af of I. brexioides .................................. :-:........... 4 2 Figure 22. Parad e rmal s e ction of a marginal crenation of a leaf of I. brexioides ............................... 42 Figure 23. Transverse section of the secondary xylem of I. brexioides ......................................... 4 2 Figure 24. Radial section of the secondary xylem of I. brexioides ........................................... :-:.. 4 2 Figure 25. Tangential s e ction of the secondary xylem of I. brexioides ......................................... 4 2 Figure 26. Radial section of the secondar y xylem of!:_ brexioides . .............................................. 4 2 Figure 27. Leaf of Bauera rubioides ...... . .............. 52 Figure 28. Diversity of leaf shapes in~ capitata ...... 52 Figure 29. Vein ending of~ rubioides .................. 52 Figure 30. Diagrammatic representation of a node and the nodal pattern of rubioides ........................ 54 Fia u re 31. Transverse section of a leaf of B . ., capitata ................................................. 56 Figure 32. Transverse section of a leaf of~ capitata showing prismatic crystals near a vascular bundle ........ 56 Figure 33. Transverse section of a leaf of~ sessiliflora ............................................. 56 Fiaure 34. Trans v erse section of a leaf of B . ., sessiliflora ............................................. 56 Figure 35. Paradermal section of th e abaxial epidermis of a leaf of B. rubioides ....................... . ........ 56 Figure 36. Transverse section of the abaxial epidermis of a leaf of B. capitata ................................. 56 vii

PAGE 8

Figure 37. Marginal serration of a leaf of B. rubioides ................................... :-=........... 56 Figure 38. Transverse section of a leaf of B. capitata .................................... :-=.....•..... 56 Figure 39. Transverse section of the secondary xylem of rubioides . ................................... ......... 5 8 Figure 40. Radial section of the secondary xylem of B. rubioides ............................................ -:-: . . 5 8 Figure 41. Radial section of the secondary xylem of B. sessiliflora ......................................... -:-: . . 58 Figure 42. Tangential section of the secondary xylem of B. sessiliflora ....................................... 58 Figure 43. Leaf of Anopterus glandulosus ................ 68 Figure 44. Vein ending of~ glandulosus ................ 68 Figure 45. Transverse section of a node of A. glandulosus ................................. :-:........... 68 Figure 46. Transverse sections of a petiole of A. glandulosus ..................................... ....... 68 Figure 47. Transverse sections of a petiole of A. rnacleayanus ..................................... :-=....... 68 Figure 48. Transverse section of a leaf of A. gl andul osus ................................. :-:........... 7 0 Figure 49. Transverse section of the rnidvein of a leaf of !::...:_ glandulosus ........................................ 70 Figure 50. Transverse section of the rnidvein of a leaf of !::...:_ mac 1 ea ya nus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 0 Figure 51. Transverse section of the abaxial epidermis of a leaf of !::...:_ glandulosus .............................. 70 Figure 52. Marginal crenation of a leaf of glandulosus .............................................. 70 Figure 53. Paraderrnal section of a marginal crenation of a leaf of glandulosus .............................. 70 Figure 54. Transverse section of the secondary xylem of!::...:_ glandulosus ........................................ 72 Figure 55. Radial section of the secondary xylem of !::...:_ glandulosus ........................................... 72 viii

PAGE 9

Figure 56. Tang e ntial s e ction of th e s ec ondary xy l em of glandulosus ........................................ 7 2 Figure 57. Radial section of th e secondar y xylem of A. glandulosus .......................................... :-:. . 7 2 Figure 58. Leaf of Cuttsia viburnea ..................... 80 Figure 59. Vein ending of viburnea ................... 80 Figure 60. Transverse sections of a node and petiole of C. viburnea ........................................... 80 Figure 61. Transverse s e ction of a leaf of C. viburnea .................................... :-:........... 82 Figure 62. Crystal sand in the s p ongy mesophyll layer of a leaf of C. viburnea ................................. 82 Figure 63. Transverse section of the midvein of a leaf of C. viburnea ........................................... 82 Figure 64. Paradermal section of the abaxial epidermis of a leaf of C. viburnea ................................. 82 Figure 65. Marginal serration of a leaf of C. viburnea . ................................... :-:........... 8 2 Figure 66. Transverse section of the secondary xylem of C. viburnea ........................................... 84 Figure 67. Radial section of the secondary xylem of C. vi burn ea ............................................. :-:.. 8 4 Figure 68. Tangential section of the secondary xylem of C. viburnea ........................................... 8 4 Figure 69. Radial section of the secondary xylem of C. viburnea ............................................. :-:.. 8 4 Figure 70. Figure 71. Leaf of Abrophyl 1 um ornans ................... 9 2 Vein endino of A. ornans ..................... 92 J Figure 72. Transverse sections of a node and petiole of A. ornans ............................................. 92 Figure 73. Transverse section of a leaf of A. ornans .... 94 Figure 74. Transverse section of a midvein of a leaf of A. ornans ............................................. 94 Figure 75. Transverse section of the abaxial epidermis of a leaf of Fi. ornans ................................... 94 ix

PAGE 10

Fig u re 76. Tr ans v e rs e s e c t i on of t he s e condar y xy l e m o f A. orna n s ............................................. 94 Figur e 77. R a dial s e ction o f t he secondar y x y le m of A. ornans ................................................ 94 Figure 78. Tangential s e ction of the secondary xylem of A. ornans ............................................. 94 Figure 79. Leaf of Carpodetus serratus ................. 105 Figure 80. Do m atiu m in th e a xi l of a secondary vein of C. serratus .......................................... 105 Figure 81. V e in ending of serratus .................. 105 Figure 82. Transverse s e ctions of a node and petiole of C. serratus .......................................... 105 Figure 83. Transverse section of a leaf of C. serratus .................................... :-:.•........ 107 Figure 84. Transverse section of a leaf of C. serratus .................................... :-:.......... 107 Figure 85. Transverse section of a midvein of a leaf of C. serratus .......................................... 107 Figure 86. Marginal serration of a leaf of~ serratus ................................................ 107 Figure 87. Transverse s e ction of the secondary xylem of C. serratus .......................................... 109 Figure 88. Transverse section of the secondary xylem of major ............................................. 10 9 Figure 89. Radial s e ction of the secondary xylem of of C. arboreus .......................................... 109 Figure 90. Tangential section of the secondary xylem of C. serratus .......................................... 109 Figure 91. Leaf of Corokia macrocarpa .................. 120 Figure 92. Leaf of C. carpodetoides .................... 120 Figure 93. Vein ending of C. macrocarpa ................ 120 Figure 94. Transverse sections of a node and petiole of f_:_ macrocarpa ........................................ 12 0 Figure 95. Transverse sections of a node and petiole of C. virgata ........................................... 122 X

PAGE 11

Figure 96. Transverse s e ction of a leaf of C. carpodetoides ............................... :-:. ......... 12 2 Figure 97. Transverse section of a midvein of a leaf of virgata ........................................... 122 Figure 98. Transverse section of a mid v ein of a leaf of macrocarpa ........................................ 122 Figure 99. Transverse section of a leaf of C. ma c r o ca r pa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . :-:. . . . . . . . . . 1 2 4 Figure 100. Paradermal section of the abaxial epidermis of a 1 eaf of macrocarpa .................... 12 4 Figure 101. Transverse section of the abaxial epidermis of a leaf of virgata ....................... 124 Figure 102. Multicellular, T-shaped trichome of C. macrocarpa ....................................... :-: . .... 12 4 Figure 103. Multicellular, T-shaped trichome of C. virgata .......................................... :-: . .... 124 Figure 104. Multicellular, T-shaped trichome of C. macrocarpa ....................................... :-: . ... . 124 Figure 105. Pitting between the terminal cell and the uppermost stalk cell of a T-shaped trichome of macrocarpa ........................................... 124 Figure 106. Transverse section of the secondary xylem of C. buddleioides ...................................... 126 Figure 107. Transverse section of the secondary xylem of C. collenettei ....................................... 126 Figure 108. Radial section of the secondary xylem of C. collenettei ....................................... 126 Figure 109. Tangential section of the secondary xylem of C. whi teana .......................................... 12 6 Figure 110. Leaf of Argophyllum cryptophlebum .......... 136 Figure 111. Vein ending of~ nullumense ............... 136 Figure 112. Transverse sections of a node and petiole of A. nullumense ........................................ 136 Fiaure 113. Transverse section of a leaf of A. nu 11 um en s e . . . . . . . . . . . . . . . . . . . . . . . . . . . :-: . . . . . . . . 1 3 8 Figure 114. Transverse section of the midvein of a leaf of A. nullumense ................................... 138 xi

PAGE 12

Figure 115. Transverse s e ction of the abaxial e p idermis of a leaf of A. nullumense .................... 138 Figure 116. Pitting between the terminal cell and uppermost stalk cell of a T-shaped trichome of !l:.._ cryptophlebum ........................................ 138 Figure 11 7. Margina 1 serration of a leaf of A. cryptophlebum ................................ -:-: . ........ 138 Figure 118. Transverse section of the secondary xylew of A. nullumense ........................................ 140 Figure 119. Radial section of the secondary xylem of !l:.._ ellipticum ........................................ 140 Figure 120. Tangential section of the secondary xylem of !l:.._ ellipticum ........................................ 140 Figure 121. Radial section of the secondary xylem of !l:.._ ellipticum ........................................ 140 Figure 122. Leaves of Donatia novae-zelandiae .......... 147 Figure 123. Portion of a lamina of D. novaezelandiae ........................... -:-=................. . 14 7 Figure 124. Unilacunar, one-trace nodal pattern of D. novae-zelandiae ...............................•...... 14 7 Figure 125. Transverse section of a leaf of D. novaezelandiae .................................... -:-=......... 14 7 Figure 126. Portion of lamina of D. novae-zelandiae proximal to the leaf apex ......... -:-:.................... 147 Figure 127. Lignified parenchyma cells abaxial to vascular bundles in leaves of D. novae-zelandiae ........ 149 Figure 128. Paradermal section of a leaf of D. novaezelandiae .................................... -:-=......... 149 Figure 129. Transverse section of the abaxial epidermis of a leaf of D. novae-zelandiae ............... 149 Figure 130. Multicellular, uniseriate trichome of D. novaeze l andiae .................................... -:-: . .. 14 9 Figure 131. Transverse section of a stem of D. novaezelandiae . ................................... -:-=........ . 14 9 Figure 132. Radial section of the secondary xylem of D. novae-zelandiae ...................................... 149 Xll

PAGE 13

1 Fig u re 133. Leaf of Anodopetalum biglandulosum ......... 157 Figure 134. Vein ending of~ biglandulosum ............ 157 Figure 135. Transverse sections of a node and pet i o 1 e of big 1 and u 1 o sum ............................. 1 5 7 Figure 136. Transverse section of a leaf of A. biglandulosum ................................ ~........ 159 Figure 137. Transverse section of a midvein of a leaf of~ biglandulosum ..................................... 159 Figure 138. Marginal crenation of a leaf of bigl andulosum ........................................... 15 9 Figure 139. Transverse section of the secondary xylem of biglandulosum ..................................... 159 Figure 140. Radial section of the secondary xylem of~ biglandulosum ..................................... 159 Figure 141. Tangential section of the secondary xylem of~ biglandulosum ..................................... 159 Figure 142. Leaf of Aphanopetalum resinosum ............ 165 Figure 143. Transverse section of a stem and petiole of A . resin o sum ......................................... 16 5 Figure 144. Transverse section of the avascular st i p u 1 es of A . resin o sum ................................ 16 5 Figure 145. Vein ending of~ resinosum ................ 165 Figure 146. Transverse sections of a node and petiole of A . resin o sum ......•.................................. 16 7 Figure 147. Transverse section of a leaf of A. res in o sum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ~. . . . . . . . . 1 6 7 Figure 148. Transverse section of a midvein of a leaf of A resin o s urn . . . . . . . . . . 1 6 7 Figure 149. Marginal serration of a leaf of A. resinosum .................................... ......... 16 7 xiii

PAGE 14

----Key to Tissues Nodes and Petioles Sclerenchyma Lignif ied Parenchyma ................. Uxylem Collenchyma Cork f[;fS/J Phloem From M e tcalf e and Chalk (1 9 50) with minor m odifi c ation x i v

PAGE 15

Abstract of Dissertation Pres e nted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy C0MPARA'l ' IVE ANATOMY AND SYSTEMATICS OF TWBLVE ; WOODY A U STRALASIAN GENERA OF THE SAXIFRAGACEAE By MATTHEW HENRY HILS AUGUST 1985 Chairman: Terry W. Lucansky Major Department: Botany Vegetative anatomical data are provided for twelve woody saxifragaceous genera from Australasia. These data are used, where possible, to determine the taxonomic position of these plants. The twelve genera are Tetracarpaea, Ixerba, Bauera, Anopterus, Cuttsia, Abrophyllum, Carpodetus, Argophyllum, Corokia, Donatia, Anodopetalum and Aphano petalum. Typically these taxa possess dorsiventral leaves with uniseriate epidermides and anomocytic stomatal apparatuses. The nodal pattern is either unilacunar, one-trace or trilacunar, three-trace. The wood possesses angular, soli tary pores, long vessel elements with oblique, scalariform perforation plates, tracheids with spiral thickenings and sparse axial parenchyrna. Cuttsia, Abrophyllum, Carpodetus, Ixerba, Anopterus, Corokia and Argophyllum possess most or all of eleven anatomical features of an archetypical woody xv

PAGE 16

saxifra ge . Whil e wo od anatomy i s similar a ~ on g T e tracar paea, B auera and an archet yp ical w oody saxifrag e , leaf anat o my is distincti ve for each group. Donatia, Anodopetalum and Aphanopetalum possess fe~ anato m ical features of an arch e typical wood y saxifrag e . Ixerba is anatomically iso lated from the Bre x ioidea e , but is similar to Anopterus in the Escallonioidea e . Cuttsia and Abrophyllum are very simi lar anatomically and closely related. Anatomical data do not support the maintenanc e of the tribe Argophylleae of the Escallonioideae which includes Carpodetus, Corokia and Argo phyllum. Carpodetus is more similar anatomically to Cuttsia and Abrophyllum than to Corokia and Argophyllum. Corokia and Argophyllum are very similar anatomically and probably closely related, but their taxonomic position remains obscure. Anatomical data support the union of the genus Argyrocalymma with Carpod e tus, and the union of the genus Colmeiroa with Corokia. Tetracarpaea and Bauera are anatom ically distinctive and isolated gen e ra and may deserve fa milial status. Tetracarpaea is more closely allied to the Saxifragacea e based upon its wood anatomy, while Bauera is more closely allied to the Cunoniaceae because of its oppo site leaves and foliaceous stipules. The nodal, leaf and wood anatomy of Anodopetalum is more similar to that of the Cunoniaceae than to that of the Saxifragaceae. Aphano petalum and Donatia are readily distinguishable and isolated from the Saxifragaceae, but their taxonomic positions remain obscure. Donatia should probably be placed in its own family, but Aphanopetalum r ema ins an enig ma . xvi

PAGE 17

INTRODUCTION Systematics of the Saxifragaceae Although the family Saxifragaceae, sensu lato, is cos mopolitan, most species occur in temperate regions. The family contains trees, shrubs, vines, and herbs, and approx imately 40 genera contain woody species. The taxonomic problems in the Saxifragaceae are numerous and well known (e.g., Cronquist, 1968; Dahlgren, 1975; Stern, 1974b; Takhtajan, 1980; Thorne, 1976, 1983), and occur at almost every taxonomic level. According to Engler (1928), the family consists of 15 subfamilies, 80 genera and approximately 1200 species. Thorne (1976, 1983) and Schulze-Menz (1964) also recognize a single large family that consists of 13-17 subfamilies and 78 to 80 genera. Other taxonomists have divided this group of plants into either a few families (Cronquist, 1968, 1981; Hutchinson, 1967) or many families (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan 1966, 1980, 1983). These smaller families usually correspond to Engler's (1928) subfamilies (Takhtajan, 1980), but may be much more inclusive (Cronquist, 1981). Despite these differing opinions concerning the number of families, most taxonomists agree that the Saxifragaceae belong to the order Rosales (Engler, 1928; Schulze-Menz, 1

PAGE 18

2 1964; Cronquist, 1981; Thorne, 1983), or the roughly equivalent order Saxifragales (Takhtajan, 1980). Dahlgren (1975, 1980, 1983), however, deviated from this consensus and split the various families into two superorders (Rosi florae and Corniflorae) distributed among three orders (Cunoniales, Saxifragale s , and Cornales). Hutchinson (1967) divided Saxifragaceae along herbaceous and ligneous lines, and placed the corresponding genera into his Saxifragales and Cunoniales, respectively. In addition to these largely unresolved taxonomic prob lems, the placement and delimitation of several genera is questionable. Bauera, for example, has been placed in the Saxifragaceae (Engler, 1928), the monogeneric Baueraceae (Hutchinson, 1967), and the Cunoniaceae (Cronquist, 1981). Aphanopetalum is another genus often placed in the Cunonia ceae, but its affinities are questionable (Dickison, 1980b). Donatia is also enigmatic. Engler (1890) originally placed this genus in the Saxifragaceae, but later (1928) was uncer tain of its affinities. Other taxonomists have placed Donatia in the Stylidiaceae (Mildbraed, 1907; Thorne, 1976, 1983; Dahlgren, 1975, 1980, 1983) or in the monogeneric Donatiaceae (Cronquist, 1981). Another bewildering genus, Corokia, has been shuttled among the Saxifragaceae (Engler, 1928), Escalloniaceae (Takhtajan, 1980), Cornaceae (Cronquist, 1981), and Corokiaceae (Dahlgren, 1983). In addition, Corokia carpodetoides was originally the basis of a separate genus, Colmeiroa (Engler, 1928), although Smith

PAGE 19

3 (1958) more recently has combined this g e nus with Corokia. Similarly, the genus Argyrocalymma, endemic to New Guinea, has been reduced to a section of the genus Carpodetus (Engler, 1928; Reeder, 1946; Schlechter, 1914). Hydrangea also has been divided into two sections, Hydrangea and Cornidia (Mcclintock, 1957), and each of these sections has at times been elevated to the generic level (Small and Rydberg, 1905). Anatomical Work on the Saxifragaceae Early anatomical studies of the Saxifragaceae are those of Thouvenin (1890) and Holle (189 3 ). These workers noted that, despite their anatomical heterogeneity, the woody saxifragaceous genera typically share the following charac teristics: scalariform perforation plates, three vascular traces at the base of a petiole, and a stomatal apparatus without subsidiary cells. In addition, trichomes vary from simple, unicellular to branched, multicellular or glandular, multicellular types. Prismatic crystals, druses, raphides, or crystal sand also occur. Thouvenin (1890) recorded anatomical descriptions of stems and leaves for Ixerba, Bauera, Anopterus, Abrophyllum, and Donatia along with other mostly herbaceous Saxifraga ceae. He concluded that the escallonioid and brexioid gen era (i.e., Ixerba, Anopterus, and Abrophyllum) were a cen tral group and all other tribes should be arranged around them. Donatia and two other genera of the herbaceous tribe Saxifrageae were thought to provide a link to Brexieae

PAGE 20

4 (through Roussea) b e cause these g en era p o ss es s secretory cells in the internal portions of the cortex. Holle (1893) emphasized th e anatomy of stem, leaf, and cork of various herbaceous and woody saxifrages including Bauera, Anopterus, Abrophyllum, Argophyllum, Carpodetus, and Anodopetalum. Within all of these genera, cork originates subepidermall y . Holle grouped Argophyllum and Abrophyllum together because th e y lacked crystals. He also placed Car podetus and Anopterus relativel y close together because they possess druses and simple hairs. Anodopetalum and Bauera were isolated from the other four genera and separated from one another because the former has both simple crystals and druses, while the latter only has simple crystals. Zemann (1907) elaborated on the anatomy of Argophyllum in her monograph of the genus. She divided Argophyllum into two sections, Brachycalyx and Dolichocalyx, based upon the length of the calyx relative to the corolla. Zemann also noted that the leaves of species in section Brachycalyx either possess a bito triseriate hypodermis or palisade cells that are very short and square in transection, whereas the leaves of species in section Dolichocalyx lack a hypo dermis and possess columnar palisade cells. In his systematic anatomical summary of the dicotyle dons, Solereder (1908) considered all of the above genera to be saxifragaceous. He also included the monotypic genus Colmeiroa among the Saxifragaceae, and noted that according to Engler, this genus possesses two-armed trichomes.

PAGE 21

5 Watari (1939) investigated the leaf anatomy of so m e Saxifragaceae, including Ixerba, Bauera, Corokia, and Carpodetus. Except for Bauera, these genera possess penninerved, simple leaves, trilacunar nodal patterns and bifacial petioles. Bauera possesses palmately compound leaves, unilacunar nodal patterns and bifacial petioles. In addition, the foliar vascular bundles of these genera exhibit radial rows of xylary elements and fairly regular to irregular starch sheaths adjacent to the pericycle (Watari, 1939). Swamy (1954) studied nodal and petiolar vasculature of the Escallonioideae and reported unilacunar, one-trace nodal patterns in Abrophyllum and Tetracarpaea and trilacu nar, three-trace nodal patterns in Ixerba, Anopterus, Cuttsia, Argophyllum, Corokia and Carpodetus. A pentalacu nar nodal pattern was noted for Argophyllum laxum. Swamy (1954) indicated that the petiole patterns were similar among certain groups of genera with unilacunar and trilacu nar nodal configurations. As part of a comparative study of the wood anatomy of the Moraceae and alleged allies, Tippo (1938) briefly described the wood of the Hydrangeaceae, Grossulariaceae, sensu stricto, and Escalloniaceae based upon a few species from each family. All three families are characterized by mostly solitary, angular, thin-walled, small-diameter pores. Vessel elements are medium to long and have predominantly scalariform perforation plates. Imperforate elements are mostly tracheids and fiber-tracheids and axial parenchyma is sparse. Xylem rays are heterogeneous with sheath cells

PAGE 22

6 usually present. He concluded that a clos e relationship exists b e tw ee n the Escalloniaceae and Grossulariaceae, and somewhat less affinity occurs between the Escalloniaceae and H y drangeaceae. Also, the family Escalloniaceae is the most advanced of these three families. Metcalfe and Chalk (1950), in their survey of the vegetati ve anatomy of the d i cotyledons, did the last broad treatment of the anatomy of the Saxifragaceae. Based upon their anato m ical summaries, they placed Bauera in the Saxifragaceae, sensu stricto, Anopterus, Abrophyllum, Argophyllum, and Carpodetus in the Escalloniaceae, Corokia in the Cornaceae, Anodopetalum in the Cunoniaceae, and Donatia in the Stylidiaceae. Anatomical Work on New Zealand Genera Certain studies of the woody plants of New Zealand include the genera Carpodetus, Ixerba, and Corokia (Brook, 1951; Butterfield and Meylan, 1976; Meylan and Butter field, 1978; Morrison, 1953; Ohtani, Meylan and Butter field, 1983; Patel, 1973a, 1973b; Robinson and Grigor, 1963; Sampson and McLean, 1965). Some of these studies have provided systematic conclusions based upon anatomical data (Brook, 1951; Patel, 1973a, 1973b). Brook (1951) studied the vegetative anatomy of the endemic Carpodetus serratus and supported its placement in the Escalloniaceae because of its wide rays, vessel elements with scalariform perforation plates, and large bordered pits in the wood fibers. Patel (1973b) in v estigated the wood anatomy of the

PAGE 23

7 Escalloniaceae, including Carpodetus serratus and the mono typic Ixerba brexioides. Both species possess narrow, angu lar pores, and vessel elements with scalariform perforation plates. Xylem ra y tissue is heterogenous type II. The wood of Carpodetus, however, possesses some very wide rays, whereas the wood of Ixerba possesses only narrow rays. Patel (1973b) concluded that both genera belonged in the Escalloniaceae, although Ixerba was less primitive than Carpodetus. Although Corokia is widely distributed in the South Pacific Islands, its center of diversity is New Zealand (Allan, 1961). In his study of the Cornaceae Sertorius (1893) described the leaf and stem anatomy of two species of Corokia. He noted, as have other workers (Eyde, 1966; Weiss, 1890), the distinctive, multicellular, T-shaped tri chomes in this genus. Sertorius further described the leaves of Corokia with their unito biseriate palisade mesophylls, uniseriate epidermides, and sclerenchymatous bundle sheaths surrounding the vascular bundles. He charac terized Corokia wood as fine-textured, consisting of numer ous, thick-walled fibers bearing circular-bordered or simple pits and solitary, narrow, angular pores. Vessel perfora tions are scalariform with 10-20 thin bars per plate. Later studies of the wood anatomy of the Cornaceae (Adams, 1949; Li and Chao, 1954; Patel, 1973a) also have provided descriptions of some species of Corokia. Adams (1949) placed this genus in the Cornaceae near Cornus. While Li

PAGE 24

8 and Chao (1954) ackn owledged s cme affinity between Corokia and Cornus, they also noted a close similarity between the wood of Corokia and the wood of Saxifragaceae. Patel (1973a) noted septate fiber-tracheids in the wood of Corokia, and concluded that affinities with either the Cornaceae or the Escalloniaceae were unsatisfactory for this problematic genus. Descriptions of the distribution and development of anomycytic stomatal patterns on the leaves and flowers of Corokia also have been made (Bhatnagar, 1973; Kapil and Bhatnagar, 1974 ). Eyde (1966) excluded Corokia from the Cornaceae based upon floral morphology and anatomy. He argued for an affinity between Corokia and Argophyllum based upon floral anatomy and the presence of multicellular, T-shaped tri chomes and septate fiber-tracheids in both genera. Although both genera are included in Engler's (1928) Saxifragaceae, subfamily Escallonioideae, Eyde questioned the validity of this taxonomic arrangement. Another genus that occurs in New Zealand is Donatia. Mildbraed (1907) used vegetative and reproductive anatomical characteristics and traditional morphological characters to include Donatia in the Stylidiaceae within its own sub family, Donatioideae. Data from floral anatomy (Carolin, 1960) and embryology (Philipson and Philipson, 1973) also support inclusion of Donatia in the Stylidiaceae, although Carolin discussed the possibility that this family may be closer to the Saxifragaceae rather than the Campanulaceae to which it is often allied (Cronquist, 1981). Other work on

PAGE 25

9 the vegetative anatomy of Donatia (Chandler, 1911; Rapson, 1953) has revealed multicellular, uniseriate trichomes, tannin cells, a lignified endodermis, vessel elements with scalariform perforation plates and sclerenchyma associated with the foliar veins. Based upon these data, these workers support the separation of the Donatiaceae from the Stylidiaceae, although they emphasize that a close taxonomic relationship exists between these two families. Both studies also rejected any saxifragaceous affinities for Donatia. Carlquist (1969), however, has noted morphological similarities between Donatia and the Saxifragaceae. Anatomical Work on the Cunoniaceae The family Cunoniaceae is usually regarded as a close relative of the Saxifragaceae (Cronquist, 1981; Engler, 1928; Thorne, 1983). Recent comparative floral and vegeta tive anatomical studies in the Cunoniaceae (Dickison, 1975c, 1975d, 1980a, 1980b) support the inclusion of Anodopetalum in this family but are inconclusive regarding the placement of Bauera and Aphanopetalum. Dickison (1980a) and earlier workers (Dadswell and Eckersley, 1935; Ingle and Dadswell, 1956) place Anodopetalum among the advanced members of the Cunoniaceae because the wood has numerous vessels commonly distributed in multiples with vessel elements connected by mostly simple perforation plates and opposite to alternate intervascular pitting. Fiber-tracheids, weakly heterogen eous xylem ray tissue and aggregated axial parenchyma also are present.

PAGE 26

1 0 Dickison (198 0 a, 1980 b ) stud ie d th e no da l a nd wood anatomy of Bauera sessiliflora. The presenc e of unilac u nar, one-trace nodes and lack of interp e tiolar stipules made an affinit y to the Cunoniac e ae doubtful. Ne v erthele s s, he noted that the wood anatomy is not inconsistent with that found in other ad v anced cunoniace o us woods. Based upon floral anatomy, Dickison (1975b) supported the inclusion of Bauera in the Saxifragaceae, whereas Bensel and Palser (1975c) favored a placement in the Cunoniaceae. These work ers have emphasized the need for further critical study of Bauera. Carey (1938) reported a brief anatomical descrip tion of the leaves of Bauera rubioides from two different habitats, and characterized this species as sclerophyllous. Based upon study of leaf and nodal anato m y in Aphano petalum, Dickison (1975c, 1980b) found no affinity of this genus to the Cunoniaceae b e cause of its unilacunar, one trace nodes, lack of stipules, leaf epidermal cells with undulate anticlinal walls, and its scrambling viny habit. He offered no other taxonomic placement for this genus. Rationale for the Present Study The Saxifragaceae, sensu lato, are certainly in need of systematic study. Stern (1974b) asserted that our failure to sort out plants assigned to Saxifragaceae has given rise to various classification schemes typically based upon simi lar, morphological data which emphasize floral morphology. He stated that solutions to the taxonomic problems will develop only from analysis of n e w data and novel methods of

PAGE 27

11 interpreting old data rath e r th a n from r ew orking old data using time-worn procedures. He suggest e d inte ns i ve st u dies in plant anatomy as one m e ans of securing new data. The application of comparativ e anato m ical data to the solution of taxonomic and phylogenetic problems in plants is well known (Bailey, 1944; Carlquist, 1961; Metcalfe and Chalk, 1950, 1979, 1983; Stern, Brizicky, and Eyde, 1969). Details of vegetative anato m y, particularly wood anatomy, have been shown to be especially useful in taxonomic and phylogenetic interpretations of various plant groups without bias or preconception from earlier classification systems (Dickison, 1975a; Stern, 1978b; Tippo, 1938). A recent application of the comparative anatomical method in the Saxifragaceae is a study of Hydrangea (Stern, 1978a). The purpose of this work is to provid e vegetative anatomical and morphological data, especially wood anatomy, for twelve woody saxifragaceous genera that occur in Australia, New Zealand, New Guinea, New Caledonia and some smaller South Pacific islands, and to use these data, where possible, to determine the taxonomic position and evolution ary relationships of these plants. Although various anatomical studies of the Saxifragaceae have been done, a comparative, systematic study of the vegetative anatomy of these twelve genera is lacking. The generic level has been chosen as the unit of study to avoid any bias from previous classification systems. The twelve genera are listed in Table 1 according to Engler's (1928) classification system.

PAGE 28

12 This system is presented as a convenient point of reference because it is still the most comprehensive treatment of the Saxifragaceae. Because of the relatively similar geological history of the above Australasian land masses (Raven and Axelrod, 1972), these 12 genera may have undergone similar evolutionary influences and thus may exhibit many anatomical similarities. The present anatomical study should provide new perspectives to aid in delineating taxonomic affinities between and among these plants from the antipodes.

PAGE 29

Table 1. Twelve Australasian genera classified according to Engler (1928). Distribution information in parentheses: A, Australia; NC, New Caledonia; NG, New Guinea; NZ, New Zealand; PI, Other Pacific Islands; SA, South America; T, Tasmania. SAXIFRAGACEAE Subfamily Tetracarpaeoideae Tribe Tetracarpaeeae Tetracarpaea (T) Subfamily Brexioideae Tribe Brexieae Ixerba (NZ) Subfamily Baueroideae Tribe Bauereae Bauera (A,T) Subfamily Escallonioideae Tribe Anoptereae Anopterus (A,T) Tribe Cuttsieae Cuttsia (A) Abrophyllum (A) Tribe Argophylleae Argophyllum (A,NC) Corokia (A,NZ,PI) Carpodetus (NG,NZ) Incertae sedis: Donatia (NZ,SA,T) CUNONIACEAE Tribe Spiraeanthemeae Aphanopetalum (A) Tribe Cunonieae Anodopetalum (T) 1 3

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MATERIALS AND METHODS Preserved l e aves, stems and wood, and dried wood of twel v e wood y saxifragaceous gen e ra from Australasia were used in this study (Table 2). Only dried leaf and stem material of Corokia carpodetoides was available for study. These plant materials are part of an extensive collection of specimens of woody Saxifragaceae gathered through collec tion, correspondence and exchange by Professor William Louis Stern since the late 1960's. Collection information for individual specimens is included in the appendix (Table 4). The authorities for the names of the species studied are listed in Table 2 . Standard rnicrotechnical m e thods were used and are similar to those followed by Stern, Sweitzer and Phipps (1970), so that direct comparisons could be made between the present study and recent studies of the woody Saxifragaceae (Stern, 1974a, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979a, 1979b). Dried wood specimens were boiled in water to eliminate air in the tissue, and the blocks were stored in a 50:50 mixture of 95 % ethanol and glycerin. Fluid-preserved wood specimens were washed in water and kept in the same storage solution. Transverse, ridial, and tangential sections of unembedded wood samples of each specimen were made with a sliding microtome. 14

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15 Similar section s wer e pr ep ared fro m a few celloidin-e rn bedded wood samples. S e ctions were stained with Heidenhain's iron alum hematox y lin and counterstained with safranin (Johansen, 1940). Because ammoniacal iron alum dissolves oxalate crystals (Metcalfe, 1983), a few sections were dehydrated and mounted without staining. Wood sli v ers w e re macerated using Jeffrey's fluid (50:50 mixture of 10 % nitric acid and 10 % chromic acid) and stained with safranin (Johansen, 1940). Wood sections and macerations were mounted on glass slides with Canada balsam or Permount. Dried leaves and stems were boiled in water to reconstitute the tissues, fixed in a formalin-acetic acidalcohol solution and stored in 70 % ethanol. Fluid-preserved leaves and stems also were stored in 70% ethanol. Leaves were cleared using 5 % NaOH, washed in distilled water and bleached with a saturated aqueous solution of chloral hydrate (Arnott, 1959). Fully cleared leaves were washed in distilled water, stained with safranin, dehydrated and mounted on glass slides with Permount. Transverse and paradermal sections of paraffin-embedded leaves were cut on a rotary microtome, affixed to a glass slide with a modified Haupt's adhesive (Bissing, 1974), stained with iron alum hematoxylin and safranin and mounted with Canada balsam. A few leaf sections were mounted unstained to detect crystals. Freehand sections were cut of at least two nodes from a stern and at the proximal (point of attachment to stem), median (a midpoint on petiole), and distal (near lamina) p ortions of at least two petioles. These sections were

PAGE 32

16 tr ea t ed w i th an a q u e ous p hl o r o gl u cin o l solut i on follow ed b y co n c en t r ated H Cl t o d em on s t ra t e lignified regions. The nodal re g i o ns of the st e ms and p e tioles of some speci m ens also w e r e cleared and stained u s ing the above clearing procedure. Species with very short nodes and small petioles were emb e dded in paraffin and sectioned with a rotary microtom e . These sections were treated similarly to th e paraffin-embedded leaf sections. Anatomical analyses of leaves, including vascular architecture, cell and tissue types, trichomes and surface features (i.e., stomata, hydathodes, etc.), followed the terminology used by Hicke y (1979), Metcalfe (1979), Theobald, Krahulik and Rollins (1979), and Wilkinson (1979). Although developmental studies were not performed, the term biseriate epidermis was used to describe both the outermost cell layer and the subjacent cell layer in leaves where these two layers occur to b e consistent with the terminology of other recent studies of the woody Saxifragaceae (Stern, 1974a, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979a, 1979b). Measurements were made of both the long and short axes (length and width) of ten pairs of guard cells for each specimen. The nodal patterns and vasculation of the petiole were diagrammed and described following the summaries by Howard (1979a, 1979b). Characterization of the wood followed the diagnostic features set forth by Tippo (1941) and the terminology advocated by the Committee on Nomenclature, International Association of Wood Anatomists in the Multilingual Glossary

PAGE 33

17 of Terms Used in Wood Anatomy (1964). The only exception is the use of the term marginal parenchyma in p lace of either terminal or initial axial parenchyma. urements were made for each specimen: The following meas1) pore distributions were percentages based upon counts taken from ten 0.2 mm 2 microscopic fields; 2) tangential vessel diameters were determined from 50 measurements taken from cross sections; 3) wall thicknesses were based upon measurements of ten vessels and ten imperforate tracheary elements taken from cross sections; 4) lengths of cells were based upon measurements from end to end of 50 vessel elements and 50 imperforate tracheary elements taken from macerated wood; 5) number of bars per perforation plate were counted from thirty scalariform perforation plates; 6) end-wall angles of vessel elements, relative to the vertical axis of the cell, were measured for ten cells from tangential sections using an ocular goniometer; 7) vertical diameters of intervascular pits were determined from ten pits viewed in radial section; 8) length and width of xylem rays were measured from ten rays viewed in tangential section. Unless noted otherwise, the measurements reported below represent an average for all the species examined in a genus.

PAGE 34

18 Table 2 . Woody saxifragaceous s p ecies from Australasia examined anatomically: d, dried material; p, fluid-preserved material. SPECIES Abrophyllum ornans Hook. f. Anodopetalum biglandulosum A. Cunn. Anopterus glandulosus Labill. Anopterus macleayanus F.v. Muell. Aphanopetalum resinosum Endl. Argophyllum cryptophleburn Zernann Argophyllum ellipticum Labill. Argophyllum nullumense R.T. Baker Bauera capitata Seringe Bauera rubioides Andr. Bauera sessiliflora F.v. Muell. Carpodetus sp. Carpodetus arboreus (K. Schum. et Lauterb.) Schltr. Carpodetus major Schltr. Carpodetus serratus J.R. & G. Forst. Corokia buddleioides A. Cunn. Corokia carpodetoides (F.v. Muell.) L.S. Smith Corokia collenettei Riley Corokia macrocarpa Kirk Corokia virgata Turrill Corokia whiteana L.S. Smith Cuttsia viburnea F.v. Muell. Donatia novae-zelandiae Hook. f. Ixerba brexioides A. Cunn. Tetracarpaea tasmannica Hook. WOOD dp p dp dp d p p dp dp p d d dp d d a dp p dp p LEAVES a p p p p p p p p p p p p p p p p p p

PAGE 35

Introduction RESULTS Tetracarpaea Hook. The monotypic genus Tetracarpaea was described from specimens of.!:_ tasmannica and placed in the Cunoniaceae by William J. Hooker in 1840. The generic name refers to its distinctive four carpellate apocarpous gynoecium (Hooker, 1840). The genus is endemic to and occurs throughout most of Tasmania, but is absent from the east and northwest floristic zones of the island (Mosley, 1974b). Plants of T. tasmannica are small, erect bushy shrubs that commonly grow in subalpine habitats and may attain a height of approxi mately one foot (Bentham, 1864). These plants bear small, exstipulate, alternate or scattered leaves and four-merous, hypogynous, flowers arranged in racemes. Joseph D. Hooker (1865) positioned Tetracarpaea in his tribe Escallonieae, while Bentham (1864) placed this genus in his tribe Cunonieae. Both tribes are included in their order Saxifrageae (= the modern family Saxifragaceae [Stearn, 1965]). Engler (1890) placed Tetracarpaea in his inclusive rosalean family Saxifragaceae, first within the subfamily Escallonioideae, but later (1928) in its own subfamily, Tetracarpaeoideae. Schulze-Menz (1964) and Thorne (1976, 1983) have supported the later Englerian 19

PAGE 36

i 2 0 tr ea t me nt, but oth e r workers ha ve di ve rg ed from this view. H ut chinson (1967) included T e tracarpaea 1n the Escallonia ceae of his Cunoniales, while Cronquist (1981) placed it in his larg e r rosalean family, Grossulariaceae. Takhtajan (1 9 66, 1980) placed this genus in his Saxifragales, initially (1966) in the monotypic Tetracarpaeaceae, but recently (1980, 1983) in his Escalloniaceae. Airy Shaw (in Willis, 1973) and Dahlgren (1975, 1980, 1983) also con sidered this genus to form the basis of a monotypic family, and Dahlgren has tentatively placed Tetracarpaea in his Cornales. Observations Tetracarpaea possesses small, ovate, serrate, alternate leaves. The small teeth of the leaf margin are rounded. The petiole is very short and almost indistinguishable because the lamina tapers gradually toward the point of attachment of leaf to stem. Venation is simple craspedo dromous with a prominent midrib and conspicuous secondary veins that terminate at the leaf margin (Fig. 1). Vein areole development is incomplete to lacking. The veinlets are usually straight and tapered, but may be somewhat forked (Fig. 2). Vein endings consist of two to four tracheids with helical thickenings (Fig. 2). Infrequently these tracheids are accompanied by fiber-tracheids with thicker walls and oval bordered pits. The nodal pattern is unilacunar, one-trace, and a single collateral vascular bundle enters the base of a

PAGE 37

I I 21 petiole (Fi g . 3) . T wo c o llateral bundles se par ate from the mid v ein near th e base of a pe tiole, a n d a third bundle s p lits from th e midvein at a midpoint in a petiole. A median section of a petiole, therefore, shows four collateral bundles (Fig. 3) . The outermost two bundles represent th e first two bundles that diverge from the midvein. The larger of the two, central bundles represents the petiolar midvein, while the smaller bundle represents the third bundle to diverge from the midvein. All four bundles enter the lamina distall y (Fig. 3). Leaves are dorsiventral with a well-differentiated , triseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 4). The cells of the innermost layer of the palisade layer are sometimes shorter than the other typical ly columnar cells of this layer, but are distinct from the cells of the spongy mesophyll. The spongy mesophyll has more cell la y ers but is approximately the same thickness as the palisade layer (Fig. 4). The spongy mesophyll cells have various shapes and sizes and are loosely arranged with numerous, large intercellular spaces. The two cell layers adjacent to the abaxial epidermis are more tightly arranged and have smaller and fewer intercellular spaces than the remainder of the spongy mesophyll (Figs. 4 & 5). Druses commonly occur in the cells of the spongy mesophyll (Fig. 6 ) The small, arc-shaped vascular bundles of a leaf are collateral (Fig. 4). Very little secondary growth is visible within these bundles . Although bundle sheaths and

PAGE 38

22 bundle sheath extensions ar e lackin g , thick-walled abaxial fibers are present ad j ace n t to the priffiary phloem of th e midvein (Fig. 4 ). Both the adaxial and abaxial epidermal layers are uniseriate and composed of variously-shaped cells with evenly-thickened walls (Fig. 4). In surface view these cells also are variously-shaped (polygonal to elongate), and possess curved, evenly thickened, anticlinal walls. Both epidermal layers lack trichomes and are co v ered by a very thick cuticle (approximately 10 um; Fig. 5). Abundant stomata are restricted to the abaxial epidermis, and the stomatal apparatus is anomocytic. In surface view the guard-cell pair possesses an almost circular outline, while the individual guard cells are reniform. Guard-cell pairs average 30 um in length and 26 um in width (length/width ratio 1.15). In transection the guard cells are oval to circular and each cell bears a prominent, cuticular horn that represents the outer ledge overarching a stoma (Fig. 5). In cleared leaves the marginal teeth have a tumid appearance indicating the presence of hydathodes. A prominent vein extends nearly to the tooth apex (Fig. 7), but water pores associated with functional hydathodes are not distinguishable. Apical cells of the leaf teeth stain lighter in cleared leaves than surrounding cells which may indicate thinner cell walls (Fig. 7). The densely stained cytoplasm of these cells in paradermal sections of uncleared leaves may signify that this tissue is glandular.

PAGE 39

2 3 Tetracarpaea wood is diffuse po rous with poorly discernible growth rings (Fig. 8). The wood is very f in e textured with numerous angular pores (range 180-445 / mm 2 , x= 309) that ha ve extremely s m all tang en tial diameters (ra nge 11.7-23.4 um, x= 16) and walls 2.1-4.2 um (x=2.8) thick. Pores are p redominately solitary (80 % ) with radial multiples (3 % ) and clusters (17 %) of two to three pores resulting mostly from o v erlapping vessel element end walls. Rarely clusters of four or five pores are observed. Vessels are difficult to distinguish from axial parenchyma in slide Aw 27721 because the parenchyma is devoid of contents, and the slide has been stained with safranin only. Thus, counts of the number of pores per field are greatly inflated in this specimen. Vessel elements are of me d ium length (rang e 213455 um, x= 354), and very fine spiral thickenings are pres ent in some of these cells. Vessel ele me nt end walls are oblique, and end-wall angles range from 0-22 (x=l0). Perforation plates are exclusively scalariform, possess 5 to 18 bars per plate (x= 8), and the perforations are com pletely bordered (Fig. 9). Scalariform perforation plate bars are thick and may be branched in various ways to form a reticulate pattern. Occasionally two scalariform perfora tion plates occur in a vess e l element end wall. Scalari form, transitional to opposite inter v ascular pitting is confined mostly to ov e rlapping end walls of contiguous ves sel elements (Fig. 9). Pit diameter is minute and ranges from 3.2-4.2 um (x= 3.3).

PAGE 40

~-----24 Trach e ids bear circular-bordered pits with oval aper tures that extend slightly beyond the margins of the pit border (Fig. 9 ). The diameter of these pits is similar to that of the intervascular pits. Tracheids are extremely short (range 325-520 um, x= 396). Tracheid walls are relatively thick and range from 2.1-6.3 u m (x= 4). Very fine spiral thickenings ar e present in some of these cells (Fig. 10). Axial parenchyma is sparse and apotracheal diffuse or diffuse-in-aggregates. Vessel to axial parenchyma pitting is scalariform. No ergastic substances are noted in these cells. Although the xylem ray system consists of homocellular uniseriate rays of upright cells and heterocellular uniand biseriate rays, uniseriate rays predominate. Most hetero cellular rays are biseriate (Fig. 11), although these rays are two cells wide for only 1-4 cells of their length. Ray height ranges from 1-17 cells (.07-.75 mm) for hornocellular rays and from 7-31 cells (.28-1.22 mm) for heterocellular rays. Ray cells contain dark brown deposits and numerous starch grains (Figs. 9 & 11). Perforated ray cells are infrequent (Fig. 12), while sheath cells and crystals are absent. Vessel to ray parenchyma pitting is opposite to alternate. No fusion of rays is noted.

PAGE 41

Figure 1. Leaf of Tetracarpaea tasmannica. simple craspedodromous venation. XlO. Note Figure 2. Vein ending of T. tasmannica. Xl 75. Figure 3. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of.'.!'...!_ tasmannica. X3 0. Details: t, tracheids.

PAGE 42

26 a 1 .... b C d 2 3

PAGE 43

Figure 4. Transverse section of a leaf of Tetracarpaea tasmannica. XllO. Note fibers abaxial to the midvein. Figure 5. Transverse section of the abaxial epidermis of a leaf of T. tasmannica. X700. Note the guard-cell pair with prominent cuticular horns (arrows). Figure 6. Transverse section of a leaf of T. tasmannica. X437. Note druses in the spongy mesophyll. Figure 7. Marginal tooth of a leaf of T. tasmannica. XllO. Details: cuticle; midvein; ab, abaxial epidermis; ad, adaxial epidermis; c, d, druses; f, fibers; gc, guard cell; m, pl, palisade layer; sl, spongy mesophyll layer.

PAGE 44

28 5

PAGE 45

Figure 8. Transverse section of the secondary xylem of Tetracarpaea tasmannica. Xl75. Note solitary, angular pores. Figure 9. Radial section of the secondary xylem of T. tasmannica. X437. Figure 10. Secondary xylem of T. tasmannica. tracheids with spiral thickenings (arrows). X 700. Note Figure 11. tasmannica. Tangential section of the secondary xylem of T. Xl75. Note uniand biseriate rays. Figure 12. Radial section of the secondary xylem of T. tasmannica. X437. Note perforated ray cell with scalariform perforation plate. Details: p, pores; pi, pits; pc, perforated ray cell; pp, perforation plate; r, ray parenchyma; t, tracheids; v, vessel element.

PAGE 46

30

PAGE 47

31 Ixerba A. Cunn. Introduction The monotypic genus Ixerba was described by A. Cunning ham (1839) from specimens collected in Wangaroa, New Zea land. He based the generic name on an anagram of Brexia Thouars to emphasize an affinity which he believed to exist between the two genera. Ixerba brexioides is endemic to North Island, New Zealand and occurs throughout Aukland and northern Hawke's Bay Districts in hilly lowland and montane forests (Allan, 1961; Cheeseman, 1914, 1925). Plants of Ixerba are small trees with linear, opposite, alternate, or whorled, exstipulate leaves (Allan, 1961; Cheeseman, 1925). The five-merous, hypogynous, flowers are arranged in pani cles, and the fruit is a capsule. Various taxonomists have agreed with Cunningham's view that Ixerba and Brexia are closely related and have placed these genera in the subfamily Brexioideae of the Saxifraga ceae (Engler, 1928; Schulze-Menz, 1964; Thorne, 1976) or the Brexiaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966). Hooker (1865), however, included Ixerba in the tribe Escallonieae of the Saxifraga ceae, and Engler (1890) originally placed it in the Escal lonioideae of the Saxifragaceae. Recently, Thorne (1983) has changed his placement of Ixerba to the Escallonioideae. Hutchinson (1967) and Takhtajan (1980, 1983) have advocated a position in the Escalloniaceae for Ixerba, while Cronquist (1981) placed it in his Grossulariaceae.

PAGE 48

32 Observations Ixerba possesses narrowly oblong to elliptic, alter nate, opposite or whorled leaves that bear blunt, widely spaced crenations. Venation is semicraspedodromous with a prominent midrib and conspicuous secondary veins that branch to extend near the leaf margin and arch distally to join with superadjacent secondary veins (Fig. 13). Vein areole development is incomplete. Veinlets vary, from simple and straight to once, twice, or three times branched (Fig. 14). The vein endings may be branched or unbranched and tapered, and are composed of helically thickened tracheids that may be elongate, curved, forked, or irregularly shaped (Fig. 14). These tracheids often possess protuberances which are characterized by helical thickenings that differ in orienta tion from the thickenings in the remainder of the cell. Parenchymatous bundle-sheath cells and thick-walled fibers are associated with the vascular tissues in most vein endings. The nodal pattern is trilacunar, three-trace, and three collateral bundles enter a petiole (Fig. 15). These bundles fuse laterally to produce a single, large flattened bundle in the center of the petiole in median and distal sections (Fig. 15). In some petioles a median section reveals that one lateral bundle fuses with the central bundle before the other lateral bundle. In these latter petioles the large flattened bundle is only visible in more distal sections of the petiole. A very small collateral bundle splits from

PAGE 49

I I 33 each end of the larg e central p e tiolar bundle. These small accessory bundles occur lateral to the central bundle (Fig. 15) . Leaves of Ixerba are dorsiventral with a well developed, bito triseriate palisade layer and a highly lacunose spongy mesophyll layer (Fig. 16). The two upper most layers of palisade cells are typically columnar and tightly appressed, while the cells of the innermost layer are highly variable in shape, often widely-spaced, and intergrade with the adjacent spongy mesophyll cells (Fig. 16). The cells of the spongy mesophyll are highly variable in shape and size and separated by numerous, large inter cellular spaces. One or two large, yellowish, optically anisotropic, crystalloid inclusions occur in most cells of the palisade and spongy layers and both epidermides (Figs. 16 & 17). These inclusions probably are not calcium oxalate crystals because they did not dissolve in ammoniacal iron alum. All vascular bundles of a leaf are collateral and surrounded by a bundle sheath. The large, flattened, arcshaped, midvein, with well-developed secondary growth, is almost completely surrounded by thick-walled, lignified parenchyma cells (Fig. 18). This large bundle also posses ses adaxial and abaxial bundle sheath extensions composed of parenchyma and collenchyma cells. The smaller vascular bundles (secondary and minor veins) exhibit no secondary growth, have a few sclerenchyma cells adjacent to the , --'

PAGE 50

34 pri m ar y v asc u lar ti s su e s, are s u rround e d by a parench y rnatous bundle sheat h and lack bundle sheath extensions (Fig. 16). Both the adaxial and a b axial epidermal la y ers are uniseriate, and consist of mostly square to rectangular cells in transection (Fig. 16). The outer periclinal walls of all epidermal c e lls ar e slightly thickened. In surface v iew the e p id e rmal cells are square to pol y hedral with straight anticlinal walls. The cuticle is very thick ( > 5 urn), and trichornes are absent. Abundant stomata are restricted to the abaxial epider mis, and the stomatal apparatus is anomocytic (Fig. 19). In surface view guard cells are reniform, and guard-cell pairs are virtually circular in outline with an average length of 36 um and a width of 34 um (length/width ratio 1.06). In transection guard cells are o v al, and each cell bears a s m all, thin, cuticular horn that represents the outer ledge overarching a stoma (Fig. 20). Marginal crenations of Ixerba leaves contain glands that are characterized by thick-walled parenchyrna cells arranged in regular files (Fig. 21). In paraderrnal sections of uncleared leaves, the cytoplasm of these cells is very dense and stains very darkly (Fig. 22). Each crenation is supplied by an arc of vascular tissue that is derived from the union of two secondary or tertiary veins (Fig. 21). Wood of Ixerba is diffuse p orous and exhibits distinct growth rings (Fig. 23). The wood is fine-textured with very numerous angular pores (range 70-235 / rnm 2 , x= 114) that possess thin radial walls (rang e 1.1-3.7 urn, x= 1.9) and

PAGE 51

35 very small tangential diameters (range 25-55 um, x=41). The pores are predominantly solitary (76 % ), although radial multiples of two pores (2%) and clusters of two to five pores (22%) mostly due to overlapping end walls of vessel elements do occur. Vessel elements are long and range from 617-1600 um (x= 1149). Vessel elements possess oblique end walls with angles ranging from 2-18 (x= 8) and lack spiral thickenings. Perforation plates are exclusively scalariform with 1 6 7 1 th i n bars per p 1 ate ( x = 4 0 ) ( Fi g . 2 4 ) . One specimen (Aw H-20087) of Ixerba was distinct from all the others because of its exceptionally long vessel elements (range 1117-1942 um, x= 1498) and very numerous bars per scalariform perforation plate (range 47-111, x=71). Although perforations typically lack borders, perforations with borders at the ends or rarely with complete borders may be found in the narrowest vessel elements. Intervascular pitting is extremely rare and confined to overlapping vessel element end walls. When present, round to oval pits with small diameters (range 3.7-5.3 um, x= 4.5) typically occur in uniseriate files (Fig. 24). Tracheids bear circular-bordered pits with oval inner apertures that may be included within or extend beyond the margins of the pit border (Fig. 24). The diameter of these pits is similar to that of the intervascular pits. Trache ids are medium to moderately long (range 867-2084 um, x= 1438), with relatively thin radial walls (range 2.6-8.9 um, x= 4.7), and fine or coarse spiral thickenings occasionally are present.

PAGE 52

36 Axial parenchyma is sparse and predominantly apotra cheal diffuse and paratracheal scanty, although diffuse-in aggregates parenchyma may also occur. Vessel to axial pa renchyma pitting is mostly transitional or opposite, rarely alternate. No ergastic substances are noted in these cells. The xylem ray system predominantly is composed of homo cellular, uniseriate rays of upright cells and heterocellu lar, biand multiseriate rays (Fig. 25). Most heterocellu lar rays are biseriate, although some may be uniseriate. Ray height ranges from 1-15 cells (.06-1.03 mm) for homocel lular rays, 8-27 cells (.25-1.18 mm) for heterocellular uniseriate rays, and 6-52 cells (.25-2.00 mm) for heterocel lular biand multiseriate rays. Heterocellular rays range from 2-4 cells (26-70 um) wide. Very few ray cells contain dark brown deposits, and crystals are absent. Sheath cells are absent, while perforated ray cells with scalariform or reticulate perforation plates commonly occur in some speci mens (Fig. 26). The pitting between vessels and ray paren chyma and vessels and axial parenchyma is mostly transition al to opposite. All types of rays may be fused end-to-end.

PAGE 53

Figure 13. Leaf of Ixerba brexioides. Xl. Note marginal crenations and semicraspedodromous venation. Figure 14. Vein ending of!:._ brexioides. Xl75. Figure 15. Transverse sections of a node (a) and the proximal (b), median (c) and distal (d) sections of a petiole of.!.:_ brexioides. Details: f, fibers; t, tracheids.

PAGE 54

38 a 13 b -~. . C I 15

PAGE 55

Figure 16. brexioides. Transverse section of a leaf of Ixerba Xl 75. Figure 17. Optically anisotropic crystalloid from a leaf of I. brexioides. X700. Figure 18. Transverse section of the midvein of a leaf of I. brexioides. Xll0. Figure 19. Paradermal section of the abaxial epidermis of a leaf of I. brexioides. X437. Note anomocytic stomatal apparatus. Figure 20. Transverse section of the abaxial epidermis of a leaf of I. brexioides. X700. Note the guard cells with smal 1 cu ti cul ar horns (arrows). Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; er, crystal loid; gc, guard cells; lp, lignified parenchyma; pl, palisade layer; sl, spongy mesophyll layer; st, stoma; vb, vascular bundle.

PAGE 56

40 16 . ab \

PAGE 57

Figure 21. brexioides. Marginal crenation of a leaf of Ixerba XllO. Note the arc of vascular tissue. Figure 22. Paradermal section of a marginal crenation of a leaf of I. brexioides. XllO. Note apical gland. Figure 23. brexioides. Transverse section of the secondary xylem of I. Figure 24. brexioides. XllO. Note solitary, angular pores. Radial section of the secondary xylem of I. X4 37. Figure 2 5. brexioides. Tangential section of the secondary xylem of I. XllO. Note uniand biserate rays. Figure 26. Radial section of the secondary xylem of I. brexioides. X437. Note the perforated ray cell with scalariform perforation plate. Details: g, gland; p, pore; pits; pp, perforation plate; tracheid; v, vessel element; pc, perforated ray cell; r, ray parenchyma; t, vt, vascular tissue. pi,

PAGE 58

4 2

PAGE 59

43 Bauera Banks Introduction The genus Bauera was named by Sir Joseph Banks and described from specimens of~ rubioides in 1801 (Bailey, 1900; Bentham, 1864; Black, 1924; Burbidge, 1963; Willis, 1972). The generic name commemorates the botanical artists Francis and Ferdinand Bauer (Bailey, 1900; Black, 1924). The three species of this genus are endemic to southeastern Australia and Tasmania. Bauera rubioides, the most widespread species, occurs in wet places throughout Tasmania, eastern Victoria, eastern New South Wales and southeastern Queensland (Black, 1924; Bailey, 1900; Bentham , 1 8 6 4 ; W i 11 i s , 1 9 7 2 ) . Thi s species i s rare on Kangaroo Island in South Australia (Mosley, 1974a). Bauera capitata occurs in southeastern New South Wales and Fraser's Island off the coast of southeastern Queensland (Bailey, 1900; Bentham, 1864). Bauera sessiliflora is restricted to the Grampian Mountain range in western Victoria. Plants of Bauera are either prostrate or upright shrubs up to 2 m tall. All species of Bauera reportedly bear opposite, ses sile, exstipulate, three-foliolate leaves which give the appearance of a whorl of six leaves (Bailey, 1900; Bentham, 1864). Although flowers may have four to ten sepals and petals, most flowers have five to nine sepals and petals (Bailey, 1900; Bentham, 1864; Dickison, 1975b). Each flower possesses a few to many stamens and contains a

PAGE 60

44 superior to half-inferior, bicarpellate, s y ncarpous gynoe cium that ripens into a ca p sule. Bauera is co m monly grown as a greenhouse shrub (Bailey, 1944; Bailey and Bailey, 1976; Synge, 1974). Although Hooker (1865) considered Bauera an anomalous genus within the Saxifragaceae, Bentham (1864) placed it in the tribe Cunonieae of the Saxifragaceae. Two recent work ers (Cronquist, 1981; Takhtajan, 1980, 1983) have placed this genus in the Cunoniaceae, and have aligned this family within either the order Grossulariales or Saxifragales, respectively. Other systematists have placed Bauera in the monogeneric subfamily Baueroideae of the Saxifragaceae (Engler, 1890, 1928; Schulze-Menz 1964; Thorne, 1976), and included this family in the Rosales. Thorne (1983), how ever, recently has placed this genus in the monogeneric family Baueraceae, as have other workers (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Hutchinson, 1967), and they all place the Baueraceae among the Cunoniales. Wood, nodes and leaves of B. rubioides and B. sessiliflora, and nodes and leaves of~ capitata were available for study (Table 2). Unless noted otherwise, data apply to all species examined. Observations Bauera typically possesses simple, opposite, petiolate leaves, although~ rubioides may have whorled leaves. Each leaf is accompanied laterall y by two large sti p ules that are

PAGE 61

45 morphologicall y an d anato m ically similar to the leaves. Each stipule is attached to th e st e m by a v ery short stalk. Leaves of B. rubioides and~ sessiliflora are elliptic or ovate with entire to obscurely toothed margins (Fig. 27). Leaves of~ capitata may be elliptic or twoto three-lobed (Fig. 28). Venation is semicras p edodromo u s to brochido dromous in B. rubioides and B. sessiliflora with a prominent midvein and conspicuous secondary veins that either extend to the leaf margin and / or form arches with su p eradjacent secondary veins (Fig. 27). Venation is mixed craspedo dromous in~ capitata with some secondar y veins that extend to the leaf margin and others that arch distally to join with superadjacent secondary veins (Fig. 28). Vein areole development is incomplete in B. sessiliflora and lacking in both~ rubioides and~ capitata. Veinlets typically are forked or branched. Most tracheids of a v ein ending are elongate and slender with helical thickenings, while the terminal tracheids of a vein ending usually are shorter, larger in diameter and thicker-walled than the elongate tracheids (Fig. 29). The terminal tracheids have reticulate wall thickenings and may poss e ss short protuberances. The nodal pattern is unilacunar, one-trace, and this leaf trace quickly splits twice to form three traces, each of which is a collateral bundle (Fig. 30). The median trace enters a leaf, and each of th e lateral traces enters a lateral, foliaceous stipule. These bundles tra v erse the length of a short petiole or stipular stalk (Fig. 30). At

PAGE 62

46 approximately the same l eve l as th e trifurcation of the l e af trace in the stern, two branch trac e s aris e and quickly fu s e to form a cylindrical stele in the branch opposite a simple leaf (Fig. 30). Leaves of Bauera are dorsi v entral with a well differentiated, unito biseriate palisade layer and a high ly lacunose spongy mesoph y ll layer (Fig. 31). The palisade cells typically are elongate and columnar, but may be short and oval in transection. These cells may be tightly ap pressed or loosely arranged with small intercellular spaces. The cells of the spongy mesophyll have various shapes and sizes and are separated by numerous, large intercellular spaces. Prismatic crystals are common in the spongy meso phyll cells, especially near a vascular bundle (Fig. 32). The oval or round vascular bundles of Bauera leaves are collateral, and only the midvein exhibits a small amount of secondary growth. Although bundle sheaths and bundle sheath extensions are absent, thick-walled fibers commonly occur adjacent to the primary vascular tissues of each bundle (Fig. 31). The abaxial epidermis in all species is exclusively uniseriate and composed of very narrow, thick-walled cells in transection. The adaxial epidermis is uniseriate (B. capitata and~ rubioides) or biseriate (B. rubioides and B. sessiliflora). In the latter species the cells of the outermost layer of the adaxial epidermis resemble those of the abaxial e p idermis, while the cells of the innermost la y er are composed of very large, thin-walled cells

PAGE 63

47 (Fig. 33). These latter cells are very delicate and ofte n become distorted and disintegrate wh e n sectioned (Fig. 34 ) . In surface view the cells of both th e abaxial epidermis and the outermost layer of the adaxial e p idermis are variousl y shaped and possess sinuous or curved anticlinal walls. Although the cuticle is thin ( < 5 um) in all three species, it is slightly thicker on the abaxial surface of a leaf. Numerous stomata are restricted to the abaxial epider mis. The stomatal apparatus is anomocytic, although the three or four subsidary cells which surround a guard-cell pair are smaller than the other epidermal cells (Fig. 35). In surface view individual guard cells are reniform, and guard-cell pairs are elliptic to circular in outline (Fig. 35). Guard-cell-pair length averages 32 um and width aver ages 2 9 um (length / width ratio 1.10). In transection guard cells are oval, and each cell bears a large cuticular horn that represents the outer ledge overarching a stoma (Fig. 36). Unicellular, thick-walled, lignified trichomes with tapered ends are abundant on both epidermal layers and along the margins of leaves of~ rubioides and~ sessili flora, but are sparse on the leaves of~ capitata (Fig. 37). The base of each trichome is surrounded by a ring of epidermal cells which are much larger than the surrounding epidermal cells (Figs. 33 & 34). One or two adaxial epider mal cells along most of the margin of the leaves of~ capitata are expanded into a ridge which appears as an elongate or cla v ate protrusion in transection (Fig. 38).

PAGE 64

48 The apex and m arginal teeth of a lea f p ossess thick walled cells with darkly staining c y to p lasm that res em ble glandular cells (Fig. 37). Although the wood of the two species of Bauera studied is very similar,~ sessiliflora has longer vessel elem e nts and tracheids and taller rays than~ rubioides. Distinct growth layers occur in the wood of both species. The wood of B. rubioides is diffuse porous while the wood of B. sessiliflora is ring porous (Fig. 39). Both species pos sess very numerous pores, with ranges of 270-385 / mm 2 (x= 325) for B. rubioides and 185-320 / mm 2 (x= 257) for B. sessiliflora. Both species have thin-walled (range 1.1-4.2 urn, x= 2.0) angular pores with very small tangential diameters (range 18-57 um, x= 37). Pores are predo m inantly solitary (84 % ), although true radial multiples (3 % ) and clusters (13 % ) do occur. Vessel elements are medium length, howe v er, those of B. sessiliflora (range 234-780 um, x= 523) longer than those of~ rubioides (range 208-579 um, are x= 383). Vessel element end walls vary from transverse to oblique, with end-wall angles that range from 22-90 (x= 39). Perforation plates are typically simple, however sca lariform perforation plates with 1-5 thin bars may occur in both species (Fig. 40). All perforations lack borders. Very fine spiral thickenings rarely occur in the vessel elements of~ sessiliflora only. Inter v ascular pitting usually is scalariform or transitional in both species, although opposite or alternate patterns rarely occur

PAGE 65

4 9 (Fig. 40). T he dia me t e r o f th e e l o n ga t e or o v al pits is minute (rang e 3.2-7.4 u m , x= 4.7). Tracheids of both sp e cies b e ar circular-bordered pits with oval inner apertures that are includ e d within the pit border (Fig. 41). Th e diam e ter of these pits is similar to that of the inter v ascular pits. Th e tracheids of both s p ecies are v e ry short, altho u gh those of B. sessiliflora are longer (range 436-956 um, x= 721) than those of B. rubioides (range 312-650 um, x= 484). These tracheids have relatively thin radial walls (rang e 2.6-5.3 um, x= 3.7) and fine spiral thickenings. Axial parenchyma is sparse and either apotracheal dif fuse or paratracheal scanty. Vessel to axial parenchyma pitting is not visible in the material examined. Dark brown deposits co m monly occur in these cells. The xyle m ra y s y stem is com p osed mostly of homocellu lar, uniseriate rays of upright or square cells and a few heterocellular, biand multiseriate rays (Fig. 42). Homo cellular, biseriate and heterocellular, uniseriate rays are rare. The homocellular rays are slightly taller in~ sessiliflora (1-14 cells, 0.11-0.81 mm) than in B. rubioides (1-6 cells, 0.04-0.31 mm). Although heterocellular rays also are taller in B. sessiliflora (18-84 cells, 0.50-1.89 mm) than in~ rubioides (19-61 cells, 0.32-0.98 mm), the width of these rays is similar in both species (2-7 cells, 18-75 um). Dark brown deposits commonly occur in the ray cells of both species (Fig. 40). Sheath cells are absent, while perforated ray cells with simple or foraminate

PAGE 66

50 perforation plates are occasionally present (Fig. 41). vessel to ra y parenchyma pitting is scalariform to fenestri form. Both homocellular and heterocellular rays may be fused end-to-end.

PAGE 67

Figure 27. Leaf of Bauera rubioides. XlO. Note semicraspedodromous to brochidodromous venation. Figure 28. Di v ersity of leaf shapes in~ capitata. XlO. Figure 29. Vein ending of~ rubioides. helically thickened trach e ids. Details: t, tracheids. X437. Note

PAGE 68

52 27 28 / r , I 2 9

PAGE 69

I~ Figure 30. Diagrammatic representation of a node and the nodal pattern of Bauera rubioides. X30. Lea v es and stipules are not drawn to scale. Details: stipule; BT, branch trace; L, leaf; ST, stipular traces. LT, leaf trace; s,

PAGE 70

.....J u .0 54 0 0 M

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Figure 31. Xl75. Transverse section of a leaf of Bauera capitata. Figure 32. Transverse section of a leaf of~ capitata showing prismatic crystals near a vascular bundle. X700. Figure 33. Transverse section of a leaf of B. sessiliflora. XllO. Figure 34. Transverse section of a leaf of B. sessiliflora. XllO. Figure 35. Paradermal section of the abaxial epidermis of a leaf of B. rubioides. X437. Note anomocytic stomatal apparatus. Figure 36. Transverse section of the abaxial epidermis of a leaf of B. capitata. X700. Note the guard cells with prominent cuticular horns (arrows). Figure Xl75. 37. Marginal serration of a leaf of B. rubioides. Note marginal trichome. Figure 38. Transverse section of a leaf of~ capitata. Xl75. Note the protrusion (arrow) that represents a ridge of cells along the adaxial margin of a leaf. Details: ab, abaxial epidermis; ad, adaxial epidermis; c, cuticle; er, crystal; e, enlarged epidermal cells; f, fibers; g, gland; gc, guard cells; m, midvein;; pl, palisade layer; sl, spongy mesophyll layer; st, stoma; tr, trichome.

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5 6 31 ad 34 36

PAGE 73

Figure 39. Transverse section of the secondary xylem of Bauera rubioides. XllO. Note boundary of growth ring (arrow) and solitary, angular pores. Figure 4 0. rubioides. Radial section of the secondary xylem of B. Xl 75. Figure 41. Radial section of the secondary xylem of B. sessiliflora. X437. Note tracheids with circular-bordered pits and perforated ray cell with a simple perforation plate. Figure 42. Tangential section of the secondary xylem of B. sessiliflora. XllO. Note uni-, biand multiseriate rays. Details: p, pore; perforation plate; element; pc, perforated ray cell; r, ray; t, tracheid; v, pi, pits; vessel pp,

PAGE 74

58

PAGE 75

5 9 Anopterus Labill. Introduction Anopterus was described from specimens of A. glandu losus by J.-J. Labillardiere in 1804. The generic name refers to the broad, membranaceous wing on the end of each seed produced by these plants (Bailey, 1900). The type species is endemic to Tasmania where it is widespread throughout the island, especially in subalpine forests ( Bentham , 1 8 6 4 ; Mose 1 y , 1 9 7 4 b ) . The on 1 y other spec i es i n the genus,~ macleayanus, is endemic to eastern and south eastern Queensland and northeastern New South Wales, Austra lia where it occurs up to elevations of 1500 m (Bailey, 1900; Bentham, 1864; Burbidge, 1963). Plants within the genus are shrubs or small trees with alternate, simple, exstipulate leaves (Bailey, 1900; Bentham, 1864). The six to nine-merous flowers are borne in racemes, and each con tains a bicarpellate, superior ovary that ripens into a capsule. Anopterus glandulosus commonly is used in ornamen tal horticulture for its handsome evergreen foliage (Bailey 1944; Bailey and Bailey, 1976; Synge, 1974). Most taxonomists have placed Anopterus in either the Saxifragaceae, subfamily Escallonioideae (Engler, 1890, 1928; Schulze-Menz 1964; Thorne, 1976, 1983) or the Escal loniaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1980, 1983). Cronquist (1981), however,

PAGE 76

60 includ e d t his genu s i n h i s Gro s su lari a c e a e . Although most of th e se s y s te matists ha v e includ ed th e se taxa in the Rosales or some roughl y equi v alent order, some workers ha v e placed the m in eith e r th e Cunoniales (Hutchinson, 1967) or the Cornales (Dahlgr e n, 1975, 1980, 1983). Wood, lea v es, and nod e s of glandulosus and A. macleayanus w e re exa m ined in this stud y (Table 2). Unless noted otherwise, data apply to both species. Observations Anopterus macleayanus possesses very long, narrowly oblanceolate to oblanceolate leaves while A. glandulosus possesses smaller, oblanceolate leaves. The leaves of both species bear blunt crenations (Fig. 43). Venation is semi craspedodromous with a prominent midvein and conspicuous secondary veins whose b ranches extend near the leaf margin and arch distally to join with superadjacent secondary or tertiary veins (Fig. 43). Vein areoles are smaller and their development is imperfect in~ macleayanus, while they are larger and their development is incomplete in~ glandu losus. Veinlets vary from straight to once or twice branched. Vein endings are usually tapered and simple, b u t may be clavate or branched. These vein endings are composed of two to eight helically thickened tracheids that usually are elongate but, may have irregular shapes (Fig. 44). Some tracheids possess small protuberances on their side walls that are characterized by helical thickenings that differ in orientation from the thickenings in the remainder of the

PAGE 77

61 cell. T h es e protu be rances are less common in!::..:_ macleayanus than in A. clandulosus. In the latter species they often correspond to the interface between two large, irregularly shaped bundle sheath cells. Bundle sheath cells are not visible in the vein endings of!::..:_ macleayanus. Although the nodal pattern is trilacunar, three-trace in Anopterus (Fig. 45), the vasculature of the petiole is very different for the two species (Figs. 46 & 47). In A. glandulosus, three collateral bundles enter the base of a petiole, traverse its entire length and enter the lamina distally (Fig. 46). Three bundles also enter the base of a petiole in A. macleayanus (Fig. 47). However, only the middle bundle is collateral, while the two lateral bundles are amphicribral (Fig. 47). Near the base of a petiole in !::..:_ macleayanus, the middle, collateral bundle enlarges to form a horseshoe-shaped or concentric central bundle with the two lateral, amphicribral bundles on either side. In the proximal half of a petiole two large gaps form in the large central bundle opposite the lateral amphicribral bun dles. The central bundle also may divide at positions other than opposite the lateral bundles. Near a median point on a petiole the two amphicribral bundles become collateral and arc-shaped with xylem internal, and each of these bundles fuses with the dissected central bundle (Fig. 47). All of the remaining bundles of the dissected central bundle fuse to form a large horseshoe-shaped bundle that enters the lamina distally (Fig. 47).

PAGE 78

62 Leaves of Anopterus are dorsiventral with a narrow, typically uniseriate, rarely biseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 48). The uppermost cells of the palisade layer are elongate and tightly appressed while the lowermost cells are shorter and more loosely arranged. These latter cells are typically inter mingled with the spongy mesophyll cells. The elongate uppermost palisade cells of~ glandulosus are somewhat longer than those of~ macleayanus. The spongy mesophyll cells have various shapes and sizes and are separated by large intercellular spaces. Druses are common in the spongy mesophyll cells of A. macleayanus, but infrequently occur in A. glandulosus. The vascular bundles of a leaf typically are collat eral, however, certain bundles (secondary veins) in~ mac leayanus are amphicribral. The midvein and larger bundles (secondary veins) of both species exhibit a moderate amount of secondary growth. The midvein of A. olandulosus is relatively small and flattened or arc-shaped (Fig. 49), whereas that of "!l:.._ macleayanus is very large and horseshoe shaped (Fig. 50). In A. glandulosus the midvein is sur rounded by thick-walled, lignified parenchyma cells adaxial ly and thin-walled parenchyma cells abaxially. Bundle sheath extensions of large diameter, thick-walled, unligni fied parenchyma cells occur abaxially and adaxially. The larger bundles in this species have thick-walled fibers adjacent to the primary phloem, and all vascular bundles, except the midvein, are surrounded by parenchymatous bundle

PAGE 79

63 sheaths without bundle sheath extensions. In~ macleayanus thick-walled fibers occur adjacent to the primary phloem of the large midvein and the amphicribral bundles (secondary veins) (Fig. 50). The ground tissue adjacent to the primary xylem and abaxial to the midvein consists of large diameter parenchyma cells (Fig. 50). Smaller, thicker-walled, unlig nified parenchyma cells occur adaxially to these large diam eter parenchyma cells. The smaller bundles (minor veins) in A. macleayanus lack bundle sheaths and extensions. Both epidermal layers are uniseriate, and their cells have various shapes in transection (Fig. 48). The cell walls of the epidermal cells are slightly thicker than those of the mesophyll cells. In surface view epidermal cells are variously shaped and generally possess sinuous anticlinal walls, although the abaxial epidermal cells of~ glandu losus may have curved anticlinal walls. The cuticle is thin (<5 um) and trichomes are absent. Numerous stomata are restricted to the abaxial epider mis, and the stomatal apparatus is anomocytic. In surface view guard cells are reniform and guard-cell pairs are virtually circular in outline. Guard-cell pairs have an average length of 36 um and a width of 34.5 urn (length/width ratio 1.04) in A. glandulosus, while those of~ rnacleayanus have an average length of 31 um and a width of 33 um (length/width ratio . 9 4). In transection guard ce 11 s are oval and thick-walled, and each cell bears a short, curved cuticular horn that represents the outer ledge overarching the stoma (Fig. 51).

PAGE 80

64 The apex and marginal crenations of Anopterus leaves contain glands at their apices. In leaf clearings these glands are characterized by dark-staining, thick-walled parenchyma cells arranged in regular files (Fig. 52). In paradermal sections of uncleared leaves, the cytoplasm of these cells is very dense and stains ver y darkly (Fig. 53). Each marginal crenation is supplied by an arc of vascular tissue that is derived from the union of two or more secondary or tertiary veins (Fig. 52). The wood of Anopterus exhibits distinct growth rings (Fig. 54). The wood of '!2.:..._ macleayanus is exclusively dif fuse porous. While wood of '!2.:..._ glandulosus is mostly semi ring porous, it also may be diffuse porous. Anopterus wood is fine-textured with very numerous angular pores (range 60210/mm2, x= 128) that possess very small tangential diame ters. Pores of~ glandulosus are narrower (range 25-47 um, x= 37) than those of~ macleayanus (range 26-68 um, x= 48). In both species pore distribution is mostly solitary (18%), although radial multiples of two to three cells (2%) and clusters of two to five cells (20%), mostly due to overlap ping end walls of vessel elements, do occur (Fig. 54). The vessel elements of both species have very thin radial walls (range 1.1-3. 7 um, x= 2. 4) and 1 ack spi ra 1 thickenings. These cells are long in both species, although they are longer in A. macleayanus (range 667-2084 um, x= 1220) than in~ alandulosus (range 483-1634 um, x= 1023). Vessel elements possess oblique end walls with angles that range

PAGE 81

, -I 65 from 3-21 (x= 10). Perforation plates are e x clusi ve ly scalariform with 7-44 bars per plate (x= 24) (Fig. 55). Bars are thin and often forked or branched. Occasionally two scalariform perforation plates occur per oblique vessel element end wall. Perforations commonly lack a border, however, in the narrowest vessel elements they may be bor dered at the ends or completely bordered. Only one specimen of A. glandulosus (F. M. Hueber 3 / 17 / 70) possesses a few thin-walled tyloses in some vessels and trabeculae in some vessels and tracheids. This specimen also is the only one with abundant fungal hyphae throughout the wood. Intervas cular pitting is uncommon in Anopterus, but, when present, these pits are very irregular and confined to overlapping end walls (Fig. 55). Intervascular pitting may be scalariform, transitional, opposite, or alternate, although transi tional and opposite are the most common patterns. These elongate or oval pits have minute to small diameters (range 3.2-7.4 um, x= 5.0). Tracheids bear circular-bordered pits with oval to slit-like inner apertures that may be included within or extend beyond the margins of the pit border. The diameter of these pits is similar to that of the intervascular pits. Tracheids are medium to moderately long, and these cells in !:..:.__ macleayanus are slightly longer (range 984-2134 um, x= 1465) than those in~ glandulosus (range 1000-1734 um, 1315). These tracheary elements have relatively thick radial walls (range 3.2-7.4 um, x= 5.2) and fine spiral thickenings (Fig. 55). x=

PAGE 82

66 Axial parenc hyma is s pa rs e and predominantly apotra cheal diffuse, although a few cells ma y be paratracheal scanty, or apotracheal marginal at the beginning of a growth layer. Vessel to axial parenchyma pitting, although rarely seen, is transitional, opposite, or alternate. No ergastic substances are noted in these cells. The xylem ray system is composed of homocellular, uni seriate rays of upright cells and heterocellular, biand multiseriate rays (Fig. 56). One very young specimen of A. macleayanus has a few heterocellular, uniseriate rays. Homocellular rays are 1-20 cells high (.10-2.83 mm) for both species of Anopterus. Heterocellular rays are taller in A. glandulosus (7-53 cells, .37-3.97 mm) than in~ macleayanus (height: 7-37 cells, .33-2.63 mm). Heterocellular rays are also a bit wider in A. glandulosus (2-10 cells, 31-187 um) than in A. macleayanus (2-3 cells, 44-62 um). These differ ences in width are relatively minor because most heterocel lular rays are 2-4 cells wide in both species. Dark brown deposits and starch grains are present in some ray cells. Sheath cells are absent, while perforated ray cells with scalariform perforation plates are occasionally present in both species (Fig. 57). Vessel to ray parenchyma pitting is transitional to mostly opposite, or alternate. All types of rays may be fused end-to-end, and all types may be split by vessels and/or tracheids.

PAGE 83

Figure 43. Leaf of Anopterus glandulosus. Xl. Note marginal crenations and semicraspedodromous venation. Figure 44. Vein ending of~ glandulosus. Xl 75. Figure 45. Trans v erse section of a node of A. glandulosus. XlO. Figure 46. Trans v erse sections of proximal (a), median (b) and distal (c) sections of a petiole of~ glandulosus. XlO. Figure 47. Transverse sections of proximal (a), median (b) and distal (c) sections of a petiole of A. macleayanus. XlO. Details: t, tracheids.

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68 45 43 ,,/ I , a a b b / C 0 C 46 47 I

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Figure 48. Transverse section of a leaf of Anopterus glandulosus. Xll0. Figure 49. Transverse section of the midvein of a leaf of glandulosus. X46. Figure 50. Transverse section of the midvein of a leaf of !:..:._ macleayanus. X46. Note secondary vein. Figure 51. Transverse section of the abaxial epidermis of a leaf of!:..:._ glandulosus. X700. Note guard cells with small cuticular horns (arrows). Figure 52. Marginal crenation of a leaf of!:..:._ glandulosus. Xll0. Note the arc of vascular tissue which vascularizes the crenation. Figure 53. Paradermal section of a marginal crenation of a leaf of A. glandulosus. Xl 10. Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundel sheath extension; be', adaxial bundle sheath extension; c, cuticle; f, fiber; g, gland; gc, guard cells; gt, ground tissue; pl, palisade layer; sl, spongy mesophyll layer; sv, secondary vein; vb, vascular bundle: vt, vascular tissue.

PAGE 86

70 48 \ 50 51

PAGE 87

Figure 54. Transverse section of the secondary xylem of Anopterus glandulosus. XllO. Note boundary of growth ring (arrow) and solitary, angular pores. Figure 55. Radial section of the secondary xylem of A. glandulosus. X437. Note spiral thickenings (arrow) in tracheids. Figure 56. Tangential section of the secondary xylem of~ glandulosus. XllO. Note uni-, biand multiseriate rays. Figure 57. Radial section of the secondary xylem of A. glandulosus. X437. Note perforated ray cell with scalariform perforation plate. X437. Details: p, pore; perforation plate; pc, perforated ray cell; r, ray; t, tracheid; pi, pits; pp,

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72

PAGE 89

7 3 Cuttsia F. v. Muell. Introduction The monotypic genus Cuttsia was described by Ferdinand von Mueller in 1865 from specimens of viburnea. The generic name commemorates J. Cutts, the treasurer of the "Ladies Leichhardt Search Expedition," a group of women who raised money to support a search expedition to account for the disapperance of Ludwig Leichhardt (Mueller, 1865; Willis, 1949). This genus is endemic to southeastern Queensland and northeastern New South Wales, Australia and occurs along mountain streams (Bailey, 1900; Burbridge, 1963). Cuttsia viburnea is a shrub or small tree bearing exstipulate, simple, alternate leaves. The five-merous flowers are arranged in panicules, and each possesses a superior ovary that ripens into a capsule (Bailey, 1900; Engler, 1928). Most systematists agree that Cuttsia belongs in either the subfamily Escallonioideae of the Saxifragaceae (Engler, 1890, 1928; Schulze-Menz, 1964; Thorne, 1976, 1983) or the Escalloniaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966, 1980). Cronquist (1968, 1981), however, placed this genus in his Grossulariaceae. Observations Cuttsia possesses simple, elliptic to ovate, serrate leaves. Venation is semicraspedodromous with a prominent

PAGE 90

74 mid v ein and conspicuo u s s e c on dar y v e ins w h ose branches extend near the leaf margin and arch distally to join with superadjacent secondary or tertiary veins (Fig. 58). Areole development is incomplete. Veinlets ma y be straight, curved, or branched one to three times (Fig. 59). Vein endings are composed of two to five helically thickened tracheids that are surrounded b y large-dia m eter parenchyma cells of the bundle sheath. These tracheids are usually elongate and possess very small protuberances whose position corresponds to the interface between two bundle sheath cells (Fig. 59). The nodal pattern is trilacunar, three-trace, and three collateral bundles enter a petiole (Fig. 60). Near the base of a petiole a very small accessory vascular bundle branches from each of the lateral bundles near the adaxial surface of the petiole (Fig. 60). Distally from the point of divergence of these accessory bundles, the three main petiolar bundles fuse laterally to form a large horseshoe-shaped vascular bundle in the center of the petiole (Fig. 60). Two bundles may split from the adaxial side of this large cen tral bundle (Fig. 60) or, in some petioles, the ends of the large central bundle may invaginate or become inrolled. In some petioles these inrolled ends may fuse to form a large, medullated concentric bundle with the xylem internal to the phloem. Distally each of the accessory bundles near the adaxial surface of a petiole splits to form two additional accessory bundles (Fig. 6 0).

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75 Leaves of Cuttsia are dorsi v entral with a well differentiated biseriate palisade layer and a lacunose spongy mesophyll layer (Fig. 61). The palisade cells adjacent to the spongy mesophyll are widely spaced and exhibit various shapes and sizes compared to the columnar and closely appressed cells of the remainder of the palisade layer {Fig. 61). The spongy mesophyll is approximately the same thickness as the palisade layer and is composed of cells of various shapes and sizes and relatively large intercellular spaces. Crystal sand occurs sporadically in the larger cells of the spongy mesophyll (Fig. 62). In addition small clusters of yellowish cells are visible throughout the mesophyll of cleared leaves (Fig. 59). The midvein of Cuttsia leaves may be arc-shaped, horseshoe-shaped with either collateral bundles or inrolled ends at the top of the horseshoe, or concentric and medullated (Fig. 63). Secondary growth is well-developed in the midvein and larger bundles (secondary veins). A large bundle sheath of thin-walled parenchyma cells surrounds each vascular bundle of a leaf (Fig. 61). Abaxial and adaxial bundle sheath extensions are associated with most bundles except for the very small veins. These bundle sheath extensions are composed of thick-walled parenchyma and collenchyma cells. The adaxial epidermis is biseriate, whereas the abaxial epidermis is uniseriate (Fig. 61). In transection the cells of the abaxial epidermis and the outermost cells of the adaxial epidermis are rectangular to oval in outline. The

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76 subjacent cells of th e adaxial epidermis are square, round, oval, or rectangular (Fig. 61). In surface view the cells of the abaxial epidermis and the outermost cells of the adaxial epidermis are variously shaped and possess curved and sinuous anticlinal walls. The cuticle overlying both epidermides is very thin (<5 um). Unicellular, elongate, bulbous-based, thick-walled trichomes with tapered ends generally are sparse on abaxial leaf surfaces, but are common along the large veins. Numerous stomata occur mostly in the abaxial epidermis, but also occur in the adaxial epidermis in association with hydathodes. The stomatal apparatus is anomocytic. Insurface view individual guard cells are reniform, and guard cell pairs are elliptic in outline (Fig. 64). Guard-cell pairs average 29 um in length and 21.3 um in width (length/ width ratio 1.36). In transection the guard cells are galeate in outline, and each cell bears a small cuticular horn that represents the outer ledge overarching the stoma. The apex and marginal teeth of a leaf of Cuttsia con tain hydathodes. A prominent vein flares as it enters each marginal tooth (Fig. 65). In leaf clearings, a callosity composed of thick-walled cells is visible at the apex of the rounded marginal serrations. These thick-walled cells stain more darkly than other cells of a tooth (Fig. 65). The wood of C. viburnea lacks growth rings (Fig. 66) and is fine-textured with numerous pores (range 10 -75/mm 2 , i= 37) that possess moderately small diameters (range 39-88 um, x= 64) and relatively thin radial walls (range 1.6-6.3

PAGE 93

77 urn, x= 3.5). Por e s ar e predo m inantly solitary (87%), although radial multiples of two pores (1%) and clusters of two to four pores (12%) mostly due to overlapping end walls of contiguous vessel elements do occur. The pores primarily are angular in outline, however some may appear circular because their corners are often rounded (Fig. 66). The vessel elements are long (range 817 to 2367 um, x= 1368) and possess steeply inclined oblique end walls. End-wall angles range from 6-30 (x= 15). Peforation plates are exclusively scalariform and possess 32-104 bars per plate (x= 57) (Fig. 67). Occasionally two scalariform perforation plates occur per oblique vessel element end wall. Scalariform perfora tion plate bars are thin and may be forked or branched. Perforations are bordered at the ends. Transitional, oppo site to alternate intervascular pitting is confined to over lapping end walls, and the pits often intergrade with the scalariform perforation plates (Fig. 67). Pits are small in diameter and range from 3.2-5.8 um (x= 4.6). Tracheids have circular bordered pits with oval aper tures that may be included within or extend beyond the margins of the pit border (Fig. 67). The diameter of these pits is similar to that of the intervascular pits. These cells are very long (range 1517-3267 um, x= 2396 um). Tracheid wall thickness varies from 3.7 to 13.7 um (x= 7.5 um). Fine spiral thickenings are present in most of these tracheary elements (Fig. 67). Axial parenchyma is sparse and mostly apotracheal dif fuse or diffuse-in-aggregates with short tangential bands

PAGE 94

78 7 of two to four cells (Fig. 66). Rarely xyle m parenchyma is paratracheal scanty. Vessel to axial parenchyma pitting is transitional, opposite or alternate. No ergastic substances are noted in these cells. Although the xylem ray system is predominantly composed of homocellular, uniseriate rays of upright cells and heter ocellular, multiseriate rays (Fig. 68), a few homocellular, biseriate rays of upright cells are present in each specimen. Ray height ranges from 2-27 cells (1.33-3.23 mm) for uniseriate rays, 4-30 cells (.65-3.92 mm) for biseriate rays, and 24-251 cells (1.40-11.37 mm) for multiseriate rays. Biseriate rays are 10-13 um wide, and multiseriate rays mostly are 3-9 cells (34-163 um) wide. One specimen (FPAw 18202) had rays up to 20 cells (650 um) wide. No ergastic substances are noted in these cells. Sheath cells completely surround the multiseriate rays (Fig. 68), and perforated ray cells with scalariform or reticulate perfora tion plates are commonly found in the uniseriate tails of multiseriate rays (Fig. 69). Vessel to ray parenchyma pitting is similar to pitting between vessels and axial paren chyma and is scalariform, transitional, opposite, or alter nate. Multiseriate rays often are split by tracheids and/or vessels, and occasionally rnultiseriate rays are fused end to-end.

PAGE 95

Figure 58. Leaf of Cuttsia viburnea. Xl/2. Note marginal serrations and semicraspedodrornous venation. Figure 59. Vein ending of C. viburnea Xl75. Note small clusters of cells in the mesophyll. Figure 60. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of~ viburnea. Xl 3. Details: cc, cluster of cells; t, tracheids.

PAGE 96

80 a b 58 C d 60

PAGE 97

Figure 61. viburnea. Transverse section of a leaf of Cuttsia Xl75. Note biseriate adaxial epidermis. Figure 62. Crystal sand (arrows) in the spongy mesophyll layer of a leaf of C. viburnea. X700. Figure 63. Transverse section of a midvein of a leaf of C. viburnea. XllO. Note the constricted nature of the adaxial bundle sheath extension. Figure 64. Paradermal section of the abaxial epidermis of a leaf of C. viburnea. X700. Note anomocytic stomatal apparatus. Figure 65. Marginal serration of a leaf of C. viburnea. XllO. Note the prominent flaring of vein andthe apical callosity. Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; ca, callosi ty; gc, guard cell; pl, palisade layer; sl, spongy meso phyll layer; st, stoma; vb, vascular bundle; v, vein.

PAGE 98

ad 1 . . ( . :;:. ; 61 63 65 _ : . . , 82 , i ) ~ ; . (_

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Figure 66. Transverse section of the secondary xylem of Cuttsia viburnea. XllO. Note solitary, angular pores and diffuse and diffuse-in-aggregates axial parenchyma. Figure 67. Radial section of the secondary xylem of C. viburnea. X437. Note fine spiral thickenings (arrow""f:'" Figure 68. viburnea. Tangential section of the secondary xylem of C. XllO. Note sheath cells. Figure 69. Radial section of the secondary xylem of C. viburnea. Xl75. Note perforated ray cell with a scalari form perforation plate. Xl75. Details: ap, axial parenchyma; p, pore; pc, perforated ray cell; pi, pits; pp, perforation plate; r, ray; sc, sheath cell; t, tracheid.

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84 '>,...---PP

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85 Abrophyllum Hook. f. Introdu _ ction The type species for this genus was first described as Brachynema ornans by Ferdinand von Mueller in 1862. Mueller, however, was unaware that Brachynema had been used previously for some South American plants in the Ebenaceae (see discussion in Bentham, 1864). Thus J. D. Hooker changed the generic designation to Abrophyllum (Bentham, 1864). The nam e A b rophyllum refers to the delicate and beautiful leaves of plants within this genus (Bailey, 1883, 1900). Because of its foliage, Abrophyllum has limited use in ornamental horticulture (Bailey, 1944; Synge, 1974). Abrophyllum contains two species, ornans and A. microcarpum, that are endemic and widespread in rainforests from eastern Queensland throu g h eastern New South Wales (Beadle, Evans and Carolin, 1972; Burbidge, 1963). Plants of Abrophyllum are shrubs or small trees with large, ser rate, alternate leaves. The five-merous flowers are ar ranged in panicles, and each possesses a superior ovary that ripens into a berry (Bailey, 1900, Bentham, 1864). Most taxonomists have placed this genus either within the Escallonioideae of the Saxifragaceae (Engler, 1890, 1928; Hooker, 1865; Schulze-Menze, 1964; T h orne, 1976, 19 8 3) or i n th e Escalloniac e ae (Air y S h aw in Willis, 1973; Dahlgr e n, 1 9 7 5 , 1 98 0, 1 983 ; H ut ch i n son, 1 96 7; T a k.h t aj a n ,

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1966, 1980). Cronquist (1981), however, has placed Abrophyllum in the Grossulariaceae. 86 The following observations are based upon specimens of A. ornans. Observations Abrophyllum ornans possesses large, ovate or elliptic, alternate leaves. These petiolate, exstipulate leaves bear small, rounded teeth along their margins, especially in the distal two-thirds of a leaf. Venation is semicraspedo dromous with a prominent midrib and conspicuous secondary veins whose branches arch distally to join with a super adjacent secondary or tertiary vein or terminate in the marginal teeth (Fig. 70). Vein areole development is incom plete. Veinlets are curved or branched and terminal vein endings taper (Fig. 71). These vein endings are composed of two to five helically thickened and usually elongate tra cheids. However, these cells may be short and often possess small protuberances which occur at the interface between two bundle sheath cells (Fig. 71). The nodal pattern is trilacunar, three-trace (Fig. 72), and three collateral vascular bundles enter a petiole. Each bundle quickly splits twice to produce three groups of three bundles each at the base of a petiole (Fig. 72). One group of bundles occurs in the center of a petiole, while the other two groups occur near the adaxial surface of a petiole (Fig. 72). Distally a small accessory bundle separates adaxially from each of the two adaxial groups of bundles.

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87 All the oth e r bundles except the accessory bundles may split again, and these resultant bundles become reoriented to form a horseshoe-shaped, central group of vascular bundles (Fig. 72). Some of these central bundles also may fuse with one another (Fig. 72). Distally this central group of bundles may undergo further reorientation and fusion to form a concentric ring of vascular bundles in the center of the petiole (Fig. 72), or the horseshoe-shaped configuration may persist. Distally each accessory bundle also branches once to form four accessory bundles near the adaxial surface of the petiole (Fig. 72). Leaves are dorsiventral with a well-differentiated biseriate palisade layer and a lacunose spongy mesophyll layer that is four cells thick (Fig. 73). The cells of the uppermost palisade layer are columnar and tightly appressed, while the cells of the innermost layer are spherical and more loosely arranged. The cells of the spongy mesophyll layer have various shapes and sizes and are loosely arranged with numerous small and large intercellular spaces. Crystal sand occasionally occurs in these spongy mesophyll cells. Enlarged, necrotic cells occur sporadically in the spongy mesophyll of both specimens examined. In addition, small clusters of yellowish cells are visible throughout the meso phyll in cleared leaves (Fig. 71). The midvein of a leaf may be represented either by a concentric, medullated bundle with xylem internal and phloem external or by a concentric ring of collateral bundles that exhibit various degrees of fusion (Fig. 74). All other

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88 vascular bundles are collateral. A small amount of second ary growth is visible in the midvein and all large bundles. A parenchymatous bundle sheath, and adaxial and abaxial bundle sheath extensions ar e associated with all vascular bundles. Bundle sheath extensions are composed of collen chyma cells around the larger bundles and parench y ma cells around the smaller bundles. Both adaxial and abaxial epidermal la y ers are uniser iate. In transection epidermal cells are square, rectangu lar or oval with evenly thickened walls (Fig. 73). In surface view, these cells are irregularly shaped with sinu ous and curved anticlinal walls. The adaxial epidermal cells are much larger than the abaxial epidermal cells. Cells of the abaxial epidermis have striations on their external surface. The cuticle overlying both epidermal layers is uniformly thin ( < 5 um). Numerous stomata occur mostly in the abaxial epidermis, but do occur in the adaxial epidermis in association with hydathodes. The stomatal apparatus is anomocytic. Insur face view guard cells are reniform and guard-cell pairs are elliptic in outline with an average length of 28.5 um and a width of 21 um (length / width ratio 1.36). In transection guard cells are oval to galeate and each cell bears a small, thin cuticular horn that represents the outer ledge over arching a stoma (Fig. 75). Unicellular, elongate, bulbous based, thick-walled trichom e s with tapered ends are abundant over the abaxial epidermis and margins of a leaf, especially along the mid v ein and secondary veins.

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8 9 The marginal teeth of a leaf c c ntain h y dathodes that are vascularized b y a wide vein and possess water pores in the adaxial epidermis. These teeth are small and rounded, and the tooth apices often are composed of dark-staining, thick-walled cells which resemble glandular tissue. Wood of~ ornans lacks growth rings (Fig. 76) and is fine-textured with very numerous angular pores (range 10110/mm2, x= 41) that possess moderately small tangential diameters (range 38-125 urn, x= 75) and thin radial walls (range 2.1-5.3 um, x= 3.6). Pore distribution is predorninantly solitary (74%), although clusters of two to three cells (24%) mostly due to overlapping oblique end walls of vessel elements do occur. Vessel elements are long (range 834-2701 um, x= 1705) and lack spiral thickenings. End-wall angles of vessel elements range from 4-22 (x= 10). Vessel element perforation plates are exclusively scalariform with numerous bars per plate (range 38-168, x= 93) (Fig. 77). These thin bars may be branched, and the perforations are bordered only at their ends. Intervascular pitting only occurs on overlapping end walls and is mostly scalariform, transitional, or opposite, although alternate patterns may occur. These oval or elongate pits have small diameters (range 3.2-7.4 urn, x= 4.8). Tracheids bear circular bordered pits with slit-like apertures that extend beyond the pit border (Fig. 77). The diameter of these pits is similar to that of the intevascu lar pits. These tracheary elements are very long (range

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90 1534-3351 um, x= 2464) and possess thick radial walls (x= 8.4 um). Coarse spiral thick enings are present in most tracheids (Fig. 77). Axial parenchyma is sparse and mostly apotracheal diffuse or diffuse-in-aggregates with short tangential bands of two to four cells forming a link between uniseriate rays (Fig. 76). Rarely xylem parenchyma is scanty paratracheal. Vessel to axial parenchyma pitting is mostly transitional or opposite, rarely alternate. Ray tissue is abundant and mostly co mpo sed of homocel lular, uniseriate rays of upright cells and heterocellular, multiseriate rays (Fig. 78). Rarely homocellular rays are biseriate. Uniseriate rays vary from 2-33 cells high (.474.92 mm) and multiseriate rays vary from 4-10 cells wide (91-429 um) and from 14-204 cells high (.53-15.40 mm). No ergastic substances are noted in these cells. Multiseriate rays are bordered by sheath cells, and perforated ray cells with scalariform or reticulate perforation plates occur occasionally in their uniseriate tails (Fig. 78). Vessel to ray parenchyma pitting is mostly transitional to opposite, although scalariform and alternate patterns may occur. Multiseriate ra y s often are split by vessels and / or tracheids, and aggregate rays are common.

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Figure 70. Leaf of Abrophyllum ornans. Xl/2. Note very small marginal serrations and semicraspdeodromous venation. Figure 71. Vein ending of~ ornans Xl75. Figure 72. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of A. ornans. XlO. Details: cc, cluster of cells; t, tracheid.

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72 a c,@@ fl) C d 92

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Figure 73. Trans v erse section of a leaf of Abrophyllum ornans. Xl 75. Figure 74. Transverse section of a mid v ein of a leaf of A. ornans. X46. Note the constricted nature of the adaxial bundle sheath extension. X46. Figure 75. Transverse section of the abaxial epidermis of a leaf of A. ornans. X700. Note guard cells with small cuticular horns (arrows). Figure 76. Transverse section of the secondary xylem of A. ornans. XllO. Note solitary, angular pores and diffuse and diffuse-in-aggregates axial parenchyma. Figure 77. Radial section of the secondary xylem of A. ornans. X437. Note spiral thickenings (arrow). Figure 78. Tangential section of the secondary xylem of A. ornans. XllO. Note sheath cells and perforated ray cells'-:Details: ab, abaxial epidermis; ad, adaxial epidermis; ap, axial parenchyma; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; gc, guard cell; p, pore; pc, perforated ray cell; pi, pitting; pl, palisade layer; pp, perforation plate; r, ray; sc, sheath cell; sl, spongy mesophyll layer; t, tracheid; vb, vascular bundle.

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94 73 ab , 74 77 ========

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95 Carpodetus J. R. & G. Forst. Introduction Although Carpodetus was described from specimens of C. serratus, which is endemic to New Zealand, (Forster and Forster, 1776), the center of diversity for the genus is New Guinea with nine species (Reeder, 1946; Schlechter, 1914). One other species, f.:.._ amplus Reeder, is endemic to the nearby Solomon Islands (Reeder, 1946). The generic name refers to the manner in which the fruit is girt by the cicatrix of the adnate calyx (Allan, 1961; Cheeseman, 1925; Forster and Forster, 1776; Laing and Blackwell, [1949]). Plants within this genus are shrubs or small trees that bear alternate, simple, exstipulate leaves (Cheeseman, 1925; Reeder, 1946; Allan, 1961). The four-, five-, or six merous flowers are arranged in panicles or corymbs, and each contains an inferior or half-inferior ovary that ripens into an indehiscent capsule. Although the genus is not economically important, the strong and tough wood off.:.._ serratus has been used for axe handles (Cheeseman, 1925). This species also has been used in ornamental horticulture (Bailey and Bailey, 1976). Originally Carpodetus was believed to be monotypic (Cheeseman 1914, 1925; Cunningham, 1839). However, some specimens from southeastern New Guinea, described as Argyro calymma K. Schumann & Lauterbach, were later reduced to Carpodetus (Engler, 1928; Schlechter, 1914), and two

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96 sections (Argyrocalymma K. Schum. & Lauterb. and Eucarpo d e tus Engl.) were recognized. Reeder ( 194 6) subsequently described three new species of Carpodetus and followed Engler (1928) and Schlechter (1914) in reducing three other species of Argyrocalymrna to Carpodetus. Presently eleven species have been described for Carpodetus, and three were examined in this study (Table 2). The type species, .G_ serratus, occurs on North, South, and Stewart Islands, New Zealand, in montane and coastal forests and along the banks of rivers and streams up to elevations of 1000 m (Allan, 1961; Cheeseman, 1914, 1925). Carpodetus major is endemic to New Guinea and is found in misty forests at elevations between 1300 and 1800 m (Reeder, 1946). Carpodetus arboreus, one of two species in the genus with four-merous flowers, is also endemic to New Guinea (Reeder, 1946). Most taxonomists have placed Carpodetus in either in the Saxifragaceae, subfamily Escalloniodeae (Engler, 1890, 1928; Schulze-Menze, 1964; Thorne, 1976, 1983) or in the Escalloniaceae (Dahlgren, 1975, 1980, 1983; Hutchinson, 1967; Airy Shaw in Willis, 1973; Takhtajan, 1966, 1980). Cronquist (1981) has placed this genus in his Grossularia ceae. While most systematists have included these taxa in the Rosales, others have placed the Escalloniaceae in the Cunoniales (Hutchinson, 1967) or the Cornales (Dahlgren 1975, 1980, 1983). Anatomical and morphological obser v ations for this genus are based upon leaves, stems and wood of C. serratus

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9 7 and wood of C. arboreus and C. major (Table 2). Unless noted otherwise, the data apply for all species examined. Observations Carpodetus serratus possesses elliptic to ovate, alter nate, petiolate leaves. The small teeth of the serrate leaves are narrow and rounded. Venation is sernicraspedo dromous with a prominent midvein and conspicuous secondary veins that terminate at a leaf margin or arch distally to join a superadjacent secondary vein (Fig. 79). These leaves also possess a few to many domatia on the abaxial surf ace in the axils of the secondary veins (Figs. 79 & 80). The domatia are small pockets lined by thick-walled epidermal cells with short, thick-walled, unicellular trichomes (Fig. 80). Vein areole development is imperfect, and veinlets are variously branched (Fig. 81). Vein endings are composed of one to four elongate, helically thickened tracheids and large, thick-walled bundle sheath cells. In some cases, these tracheids possess short protuberances along their side walls at the interface of two bundle sheath cells. The nodal pattern is trilacunar, three-trace, and three collateral bundles enter the base of a petiole (Fig. 82). These three bundles quickly fuse laterally near the base of a petiole to form a large, relatively flat, collateral bundle in the center of the petiole (Fig. 82). Two, small collateral bundles split adaxially from this large bundle (Fig. 82). These two accessory bundles and the large, central bundle of the petiole enter the lamina distally.

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9 8 Lea v es of C. s e rrat us ar e d o rsi ven tral wit h a well diff e rentiat ed bito tris e riat e p alisa de la y er and a co m pact spong y mesophyll la y er (Fi g s. 83 & 84). In transection all palisade cells are ti gh tl y a pp r e ssed, how ev er, the cells adjacent to the spong y meso p h y ll ar e sometimes shorter and wid e r than the other elon g at e , columnar palisade cells. The spong y mesoph y ll is compos e d of v ario u sl y shaped cells and very small intercellular spaces. Druses commonly occur in spongy mesoph y ll cells, but rarely occur in palisade cells. The vascular bundles of a leaf are collateral and may be round or arc-shaped. A mod e rate amount of secondary growth is evident in the larger bundles (midvein and second ary veins) (Fig. 85). These larger bundles possess a bundle sheath of thick-walled, lignified parench y ma cells. Druses rarely occur in these cells. Bundle sheath extensions com posed of thick-walled parench y ma and collenchyma cells occur both adaxiall y and abaxially. The smaller bundles (minor veins) also possess a bundle sheath and may possess a paren ch y matous bundle sheath extension adaxiall y (Fig. 84). Although the abaxial epidermis is uniseriate, the ad axial epidermis has both uniseriate and biseriate regions in transection. In most leaves the adaxial epidermis is uni seriate between the veins and biseriate above the veins (Fig. 83). However, in one specimen (B. F. Shore s.n. 4) with small, y oung leaves, the adaxial epidermis is almost entirely biseriate (Fig. 84). In transection all cells of both epidermal la y ers are square or rectangular and possess

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99 e v enl y thick ene d walls. The cells of the inner m ost layer of th e adaxial e p idermis have numerous primary pit fields in their anticlinal walls. In surface view epidermal cells are variously shaped. The outermost cells of the adaxial epi dermis possess straight or curved anticlinal walls, while the cells of the abaxial epidermis possess curved and sinuous anticlinal walls. The cuticle o v erlying both epi dermal layers is very thin (<5 um). Stomata occur mostly in the abaxial epidermis, but do occur in the adaxial epidermis in association with hyda thodes. The stomatal apparatus is anomocytic. In surface view individual guard cells are reniform and guard-cell pairs are elliptic in outline. Average guard-cell-pair length is 30 um and width is 23 um (length/width ratio 1.29). In transection the guard cells are oval to circular and each cell possesses a very small cuticular horn that represents the outer ledge overarching the stoma. Elongate, unicellular, thick-walled, bulbous-based trichomes with tapered ends are generally distributed over both epiderml layers, but are especially abundant along the major veins (Fig. 80). The trichomes associated with domatia are shorter, wider and thicker-walled than the other foliar trichomes (Fig. 80). The marginal teeth and apex of a leaf contain hyda thodes. A prominent vein flares as it enters each tooth (Fig. 86). In leaf clearings dark-staining cells, which may be glandular tissue, are visible at the apex of the marginal serrations (Fig. 86).

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100 Although Carpodetus wood is fairly uniform based upon cell types, morphology of vess e l elements and composition of ray tissue, the three species studied exhibit some differ ences in the dimensions of cells, pore density and diameter and numbers of bars per scalariform perforation plate. These differences parallel the distributions of the three species. The two species from New Guinea,~ arboreus and C. major, are very similar, while the New Zealand species, C. serratus, is distinct from them. The wood of C. serratus exhibits distinct growth lay ers, is semi-ring porous, and possesses numerous pores (range 45-185/rnm 2 , x= 99) with narrow diameters (range 26-72 urn, x= 46) (Fig. 87). The wood of~ arboreus and~ !:!!_ajor lacks growth rings and possesses fewer pores (range 1045 / mm2, x= 22; range 10-55/mm 2 , x= 27, respectively) with wider diameters (range 47-130 um, x= 94; range 52-112 urn, x= 77, respectively) than the wood of C. serratus (Fig. 88). Pores are angular in outline and predominantly solitary for all species (range 66-90 % , x= 78). Radial multiples (range 0-4%, x= 0.5) and clusters (range 10-34%, x= 21.5) of pores are mostly due to overlapping end walls of vessel elements. Vessel walls are thicker in C. arboreus (range 2.1-5.3 um, x= 3.5) and~ !!:_ajor (range 2.1-4.7 um, x= 3.4) than in C. serratus (range 1.0-3. 7 um, x= 2.4 ). Vessel elements of C. serratus are shorter (range 550-1700 um, x= 1039) than those of either C. arboreus (range 550-2217 um, x= 1593) or~ major (range 650-2084 um, x= 1409). End-wall angles range

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101 from 2.5-31 (x= 10) in C. serrattus to 7-28 (x= 15) in C. arboreus and f.:.._ major. In all speci e s the perforation plates are exclusively scalariform, the perforations have complete borders, and the bars may be forked or branched (Fig. 89). Carpodetus serratus possesses more bars per scalariform perforation plate (range 19-116, x= 54) than either C. arboreus or f.:_ major (range 16-70, x= 4 0). The perforation plates occasionally are compound with two sealariform plates in an oblique end wall. Some vessel elements of C. serratus also possess very fine spiral thicken ings, which are lacking in the other two species. Intervas cular pitting is confined to overlapping end walls of vessel elements and often intergrades with the scalariform perfora tion plates. This pitting varies from scalariform, transi tional, or opposite inf.:_ serratus to transitional, oppo site, or alternate inf.:_ arboreus and f.:_ major. Pit diame ter is largest inf.:_ arboreus (range 5.3-8.4 um, x= 6. 7) and slightly smaller in both f.:._ major (range 4.2-7.4 um, x= 5.6) and f.:_ serratus (range 4.2-6.3 um, x= 5.0). Tracheids bear circular bordered pits with oval aper tures that are either included within or extend slightly beyond the pit border. The diameter of these pits is simi lar to that of the intervascular pits. Tracheids are much longer in both f.:._ arboreus (range 1650-3051 um, x= 2355) and f.:._ major (range 1800-3601 um, x= 2591) than in C. serratus (range 1050-3601 um, x= 1700). Tracheid walls are approxi mately twice as thick inf.:.._ arboreus (range 6.3-17.9 um, x= 11.1) and f.:_ ~ajor (range 4.7-13.1 um, x= 9.1) than in C.

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102 serratus (range 3.2-8.9 um, x= 5.5). Coars e spiral thickenings typically occur in the tracheids of all three species. Axial parenchyma is sparse and predominantly apotrache al diffuse or diffuse-in-aggregates with short tangential bands of two to three cells forming a link between uniser iate ra y s (Fig. 88). X ylem parench y ma is occasionall y para tracheal scant y . Vessel to axial parench y ma pitting is mostly opposite in all three species. Rarely alternate pitting occurs inf.:_ arboreus and C. major and transitional, opposite to alternate pitting rarely is noted inf.:_ ser ratus. Dark brown deposits are present in the axial paren chyma of one specimen of C. serratus that contains numerous funga 1 hyphae. The ray system of Carpodetus is fairly uniform and composed mostly of homocellular, uniseriate rays of upright and square cells and heterocellular, multiseriate rays (Fig. 90). Homocellular, biseriate ra y s rarely occur. Uniseriate rays range in height from 1-18 cells (.60-1.78 mm), while multiseriate rays range in height from 11-402 cells (.6710.59 mm) and range in width from 2-18 cells (26-697 um). Carpodetus serratus possesses the tallest and widest multi seriate ra y s among the three species. The multiseriate rays of Carpodetus are bordered by elongate sheath cells (Fig. 90), and perforated ra y cells with scalariform or retic u late perforation plates commonl y occur among the cells of the uniseriate tails (Fig. 87). All species possess prismatic cr y stals in the square and / or procumbent cells of the

PAGE 119

103 multiseriate rays (Fig. 8 9 ) . Th e s e cr y stals are proba b l y nonoxalate because they did not dissolve in the ammoniacal iron alum used in the staining procedure. Although vessel to ray parenchyma pitting varies from scalariform and tran sitional to opposite or alternate, the most common pattern is opposite. Aggregate rays are common, and rays often are split by vessels and / or tracheids (Fig. 90).

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Figure 79. Leaf of Carpodetus serratus. Xl. Note marginal serrations, sernicraspedodrornous venation and dornatia in the axils of the secondary veins. Figure 80. serratus. Figure 81. Dornatiurn in the axil of a secondary vein of C. XllO. Note trichomes. Vein endings of~ serratus. Xl75. Figure 82. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of C. serratus. X30. Details: d, dornatia; t, tracheid; tr, trichome.

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105 79 a {Jj e b C , I , , , , ,, d 82

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Figure 83. serratus. Transverse section of a leaf of Carpodetus Xl75. Note partially biseriate adaxial epidermis. Figure 84. Transverse section of a leaf of C. serratus. Xl75. Note totally biseriate adaxial epidermis. Figure 85. Transverse section of a midvein of a leaf of C. serratus. XllO. Note the discontinuous and constricted nature of the adaxial bundle sheath extension, and the domatia on either side of the midvein. Figure 86. Marginal serration of a leaf of C. serratus. XllO. Note the apical callosity and the prominent vein which flares as it enters the serration. Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; ca, callosity; d, domatium; pl, palisade layer; sl, spongy mesophyll layer; st, stoma; vb, vascular bundle; v, vein.

PAGE 123

107 C ad pl 83 ab C ad 84 ab \ 85 86

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Figure 87. Transverse section of the secondar y x y le m of Carpodetus serratus. XllO. Note solitar y , angular pores and perforated ra y cells. Figure 88. Trans v erse section of the secondar y x y le m of C. major. Xll0. Note solitar y , angular pores and diffuse and diffuse-in-aggregates axial parench y ma. Figure 89. arboreus. Radial section of the secondary xylem of C. Xl 10. Figure 90. Tangential section of the secondar y x y lem of C. serratus. Xll0. Note uniand multiseriate ra y s, and sheath cells. D e tails: ap, axial parenchyma; pore; pc, perforated ray cell; ray; sc, sheath cell. er, prismatic cr y stal; pp, perforation plate; p, r,

PAGE 125

109

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110 Corokia A. Cunn. Introduction The genus Corokia was described by Allan Cunningham in 1839 from specimens of~ buddleioides collected in Wanga roa, New Zealand. The generic name refers to the plant's common name, korokio-taranga, used by the Maori, a Polyne sian people native to New Zealand (Cunningham, 1839). Plants of Corokia are usually shrubs, rarely small trees, with alternate, simple, exstipulate leaves (Allan, 1961; Cheeseman, 1925; Smith, 1958). The five-merous flowers are borne in axillary or terminal cymes, panicles, or racemes, and each flower possesses an inferior ovary that ripens into a drupe. Corokia has six to eight species distributed from east ern Australia and Lord Howe Island to New Zealand, Chatham Island and Rapa Island. The center of diversity for Corokia is New Zealand where three to four endemic species occur (Allan, 1961; Cheeseman, 1925). The most widely distrib uted species is~ cotoneaster which occurs throughout both North and South Islands in lowland shrub-lands, river flats, and rocky places up to elevations of 750 m. Corokia buddleioides is found only in the northern portion of Auk land District, North Island along the margins of coastal and lowland forests and in shrub-lands up to elevations of 900 rn (Allan, 1961; Cheeseman, 1925). Corokia cotoneaster and

PAGE 127

111 buddleioides readily hybridiz e where they occur together, and hybrid specimens collected in the field were described as C. cheesemannii H. Carse in 1913 (Allan, 1961; Cheeseman 1925). Another name, Corokia virgata Turrill, was applied to specimens cultivated at the Royal Botanical Gardens, Kew from cuttings of uncertain orig in ( Al 1 an, 19 61). These cultivated specimens match fairly well with the hybrid spec imens found in the field, and C. cheesemannii and f.:_ virgata may be synonyms (Allan, 1961; Cheeseman, 1925). Corokia macrocarpa, originally considered a variety of C. buddlei oides, is restricted to forests and forest margins of Chat ham Island. The westernmost representative of the genus, f.:_ whiteana, occurs in New South Wales, Australia, in rainfor ests of high elevations in the Gibbergunyah Range (Smith, 1958). Corokia carpodetoides is endemic to Lord Howe Island and was originally the basis of the monotypic genus Col meiroa (Engler, 1928; Smith, 1958). The easternmost repre sentative of this genus, f.:_ collenettei, is endemic to Rapa Island (Eyde, 1966). The New Zealand species and hybrid(s) of Corokia are commonly used in ornamental horticulture (Bailey and Bailey, 1976; Synge, 1974). Cunningham (1839) noted that Corokia had affinities to the Rhamnaceae. However, subsequent authors (Allan, 1961; Cheeseman, 1925; Harms, 1897; Hooker, 1867; Hutchinson, 1967; Melchior, 1964) ha v e placed this genus in the Corna ceae and include this family in the Cornales or some equiv alent order. Other workers have placed Corokia in either the Escalloniaceae (Airy Shaw in Willis, 1973; Takhtajan,

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112 1966, 1980, 1983), or the Escallonioideae of the Saxifra gaceae (Engler, 1928; Thorne, 1976, 1983) and include these families among the Rosales or the Saxifragales. Dahlgren (1975) originally placed Corokia in the Escalloniaceae, but later made it the basis for the Corokiaceae in his Cornales (1980, 1983). Cronquist (1981) placed this genus in his large rosalean family Grossulariaceae. A taxonomic revision of Corokia is long overdue and desperately needed to help resolve the nomenclatural problems, the uncertain limits of the genus and the lack of agreement on its familial affinities. Leaves and nodes of C. carpodetoides, macrocarpa, and~ virgata, and wood of C. buddleioides, collenettei, and C. whiteana were available for anatomical study (Table 2). Unless noted otherwise, data apply to all species examined. Observations Species of Corokia possess simple, entire, elliptic to obovate, alternate leaves. Venation is semicraspedodromous to brochidodromous with a prominent midvein and conspicuous secondary veins that form arches by joining with superadja cent secondary veins (Figs. 91 & 92). Vein areole develop ment is imperfect, and veinlets may be straight, curved, or variously branched (Fig. 93). Vein endings are composed of one to six helically thickened tracheids. Each tracheid is usually elongate, but some may be branched, curved, or clavate. In addition, some tracheids possess small

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113 protuberances in which the hel i cal thicke n ings are oriented at right angles to the rest of the spiral thickenings. The nodal pattern is trilacunar, three-trace in C. carpodetoides and f:_ macrocarpa (Fig. 94), and unilacunar, one-trace inf:_ virgata (Fig. 95). Three collateral vascu lar bundles enter the base of a petiole inf:__ carpodetoides and f:_ macrocarpa (Fig. 94). These three bundles fuse laterally approximately midway along the length of a petiole to form a single, wide, flattened, arc-shaped vascular bun dle (Fig. 94). This wide central bundle enters the lamina distally. Only one collateral vascular bundle enters the petiole inf:_ virgata (Fig. 95). This single vascular bundle extends the length of the petiole and enters the lamina distally (Fig. 95). Leaves off:_ carpodetoides, f:_ macrocarpa and f:_ virgata are dorsiventral with a weakly differentiated, bi seriate palisade layer and a lacunose spongy mesophyll layer (Figs. 96 & 97). The uppermost palisade cells are columnar, while the elongate palisade cells adjacent to the spongy mesophyll have various shapes and sizes and often intergrade with the spongy mesophyll cells. In all three species the cells in one or both layers of the palisade mesophyll typically contain dark brown deposits (Fig. 97). Most of the cells of the spongy mesophyll are isodiametric or variously shaped and separated by large intercellular spaces. Inf:_ macrocarpa and f:__ virgata, however, the spongy mesophyll cells adjacent to the abaxial epidermis are

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114 elongate periclinally and have much s m aller intercellular spaces among th em . The arc-shaped or round vascular bundles of Corokia leaves are collateral. A small amount of secondary growth is present in the midvein of~ macrocarpa (Fig. 98). The midvein is surrounded by a parenchymatous bundle sheath in virgata and~ carpodetoides or by a partial bundle sheath composed of thin-walled parenchyma cells abaxially and thick-walled, lignified parenchyma cells adaxially in macrocarpa (Fig. 98). Abaxial and adaxial bundle sheath extensions of thin-walled parenchyma cells occur around the midvein in leaves of~ carpodetoides and~ macrocarpa. In addition, the portion of a bundle sheath extension adjacent to both epidermal layers in~ carpodetoides and~ macrocarpa is composed of thick-walled parenchyma cells and collenchyma cells. Only an abaxial bundle sheath extension of thick-walled parenchyma and collenchyma cells is associ ated with the midvein in leaves of~ virgata (Fig. 97). Bundle sheaths of thin-walled parenchyma cells surround the smaller vascular bundles (secondary veins and minor veins) in the leaves of all species (Fig. 96). These smaller bundles lack bundle sheath extensions. Both epidermal layers are uniseriate. In transection epidermal cells are square or rectangular, however, the adaxial epidermal cells are much larger and have thicker walls than the abaxial epidermal cells (Figs. 96 & 97). The abaxial epidermal cells of all species have evenly thickened walls except for those abaxial epidermal cells beneath the

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115 m i dve in of l e a v es of C. macrocarp a whic h possess une v enly t h ickened out e r walls th a t r e s emb l e ridg e s in trans e ction (Fig. 99) . T he adaxial epidermal cells of C. carpodetoides and f.:._ macrocarpa have evenly thickened walls, whereas these cells inf.:._ virgata have thin anticlinal and inner peri clinal walls and very thick, cutinized outer periclinal walls (Fig. 97). In surface view the cells of both epider mides are mostly polygonal with straight to curved anti clinal walls. The cuticle is thin ( < 5 um) inf.:._ macrocarpa and C. carpodetoides , but thick ( > 5 urn) in f-=.. virgata. Abundant sto m ata occur mostly in the abaxial epidermis, but also occur in the adaxial epidermis in association with hydathodes inf.:.. macrocarpa and f.:.. virgata. The stomatal apparatus is anomocytic in the three species studied (Fig. 100). In surface view individual guard cells are reniform. Guard-cell pairs are circular in outline inf.:._ macrocarpa and f.:.. virgata while they are typically elliptic, rarely circular, inf.:.. carpodetoides (Fig. 100). In the former two species guard-cell pairs have an average length of 24 um and a width of 23 um (length/width ratio 1.04), while in the latter species they have an average length of 36 um and a width of 27 um (length / width ratio 1.33). In transection guard cells are oval, and each cell bears a small cuticular horn that represents the outer ledge overarching a stoma. In addition, inf.:.. macrocarpa and f.:.. virgata, the guard cells are elevated above the abaxial epidermis by subsidary cells which are curved or slightly enlarged (Fig. 101).

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116 Multicellular, T-shaped trichom e s with uniseriate stalks of two to six cells and an elongate, lignified terminal cell occur on th e abaxial e p idermis (Figs. 102 & 103). The terminal cell and uppermost stalk cell are separated by walls with elongate pits (Figs. 104 & 105). The abaxial leaf surfaces of C. macrocarpa and C. virgata are densely covered by T-shaped trichom e s, whereas these unique tri chomes are onl y conspicuous along the midvein and near the revolute margins of the leaves of~ carpodetoides. Hydathodes only occur in the apex of the leaves of C. macrocarpa and~ virgata. A group of thick-walled cells is present near the leaf apex off.:_ macrocarpa. Although Corokia wood is fairly uniform based upon cell types and dimensions, morphology of vessel elements, and composition of xylem ray tissue, the three species studied can be distinguished from one another based upon the mor phology of the imperforate elements present in the wood. Distinct growth layers are present in the diffuse porous wood of C. buddleioides and the semi-ring porous wood of C. whiteana (Fig. 106), but are absent from the wood of C. collenettei (Fig. 107). Axial parenchyma is absent from all three species. All species have very numerous pores per square mm, with ranges of 100-160/mm 2 (x= 140) for~ collenettei, 150-315/mm 2 (x= 217) for~ buddleioides, and 250-380 / mm 2 (x= 305) for C. whiteana. All species have thin-walled (range 1-4.2 um, x= 2.3 um), angular pores that are mostly solitary (74 % ). Occasionally true radial multiples of two to four cells occur (5 % ) (Fig. 107), while pore

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117 c lu st e rs of t wo t o fo u r c e lls (21 % ) mostly result from overla p ping v e ss e l el eme nt e nd walls. P o re diameter is very small for all thre e s pe cies. Pores are narrowest in C. whiteana (range 18-33 um; x= 24), wider in~ buddleioides (range 23-42 um; x= 33), and widest inc. collenettei (range 29-51 um; x= 40). All species possess medium to long vessel elements (range 368-1117 um; x= 784) with steeply inclined oblique end walls. End-wall angles range from 2-24 (x= 11). Perforation plates are exclusively scalariform with 13-17 thin bars per plate (x= 23) (Fig. 108). The perforations are non-bordered. Perforation plates are rarely compound with two scalariform perforation plates per oblique end wall. Some vessel elements of C. buddleioides and~ collenettei possess very fine spiral thickenings at the ends of the cells. Intervascular pitting varies from transitional, opposite, to alternate for all species, although alternate is the most common pattern. Corokia collenettei infrequently exhibits a scalariform arrangement. The diameter of these oval or elongate pits is minute (range 3.2-4.2 um, x= 3.4). All three species studied possess septate fiber tracheids that bear circular bordered pits with medium to long inner apertures that extend well beyond the pit borders (Fig. 108). The pit border is larger in the septate fiber tracheids of C. collenettei than in those of C. buddleoides or C. whiteana. The inner aperture of these pits is much longer in~ buddleoides than in~ whiteana. Corokia

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118 buddleioid e s a nd C. white ana also posses s tracheids with circular bord e red pi ts whos e in ne r apertures extend slightly b ey ond th e pit borders. Pit dia me ters for the tracheids are si m ilar to those of the inter vas cular pits, whereas pit diameters for the septate fiber-tracheids inf.:_ buddleioides and f.:_ whiteana are extremely minute. Imperforate tracheary elements for all sp e cies are moderately short to medium long (range 717-1617 um; x= 1095) with thin walls (range 3.2-7.4 um, x= 4.5). Both types of imperforat e tracheary elements typically possess coarse spiral thickenings. The xylem ray system of Corokia is composed mostly of homocellular uniseriate rays of upright cells and hetero cellular bito multiseriate rays, although each species may have a few homocellular, biseriate and heterocellular, uni seriate rays (Fig. 109). Homocellular, uniseriate rays range in height from 1-13 cells (.07-.88 mm), while multi seriate rays range in height from 6-56 cells (.23-2.33 mm) and width from 3-20 cells (21-83 um). Perforated ray cells are occasionally seen in all species (Fig. 108), while sheath cells are lacking. Dark brown deposits are abundant in most ray cells (Fig. 108), but crystals are absent. Although vessel to ray parenchyma pitting varies from tran sitional, opposite, or alternate, the most common pattern is alternate. Fusion of rays is uncommon, however, very few rays are joined end-to-end inf.:_ collenettei.

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Figure 91. Leaf of Corokia macrocarpa. Xl. Note semicraspedodromous to brochidodromous venation. Figure 92. Leaf of C. carpodetoides. Xl. Figure 93. Vein ending of C. macrocarpa with helically thickened tracheids. Xl75.Figure 94. Transverse sections of a node and proximal (b), median (c) and distal (d) sections of a petiole of~ macrocarpa. X20. Details: t, tracheids.

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. , ( 93 / / . a I @ 92 94 b C d 120

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Figure 95. Transverse section of a node (a) and a distal section of a petiole (b) of Corokia virgata. X50. Figure 96. Transverse section of a leaf of C. carpodetoides. X4 3 7. Figure 97. virgata. Transverse section of a midvein of a leaf of C. Xl 7 5. Figure 98. Transverse section of a midvein of a leaf of C. macrocarpa. X4 6. Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; pl, palisade layer; sl, spongy mesophyll layer; tr, trichorne; vb, vascular bundle.

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122 ad 95 ' , O ' ) J { ~ . ' ' , ., , 97 \.

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Figure 99. Transverse section of a leaf of Corokia macrocarpa. X700. Note the ridges on the outer tangential walls of the abaxial epidermal cells located below the midvein. Figure 100. Paradermal section of the abaxial epidermis of a leaf of C. macrocarpa. X437. Note anomocytic stomatal apparatus. Figure 101. Transverse section of the abaxial epidermis of a leaf of C. virgata. X700. Note the elevated guard cells. Figure 102. Multicellular, T-shaped trichorne of C. macrocarpa. Xl75. Figure 103. Multicellular, T-shaped trichome of C. virgata. Xl75. Figure 104. Multicellular, T-shaped trichome of C. macrocarpa. X700. Note pitting (arrow) in the walls that separate the terminal cell from the uppermost stalk cell. Figure 105. Surface view of the pits between the terminal cell and the uppermost stalk cell of a T-shaped trichorne of C. macrocarpa. Xl750. Details: ab, abaxial epidermis; gc, guard cell; gt, ground tissue; pi, pits; r, ridges; sl, spongy mesophyll layer; st, stoma; tr, trichome.

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1 24 0 ab ~ ( 103 104

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Figure 106. Transverse section of the secondary x y lem of Corokia buddleioides. Xl75. Note the boundary of a growth ring (arrow) and solitary, angular pores. Xl75. Figure 107. collenettei. of pores. Figure 108. collenettei. tracheids. Trans v erse section of the secondary xylem of C. Xll0. Note both solitar y and radial multiples Radial section of the secondary xylem of C. Xl75. Note septum (arrow) of septate fiberFigure 109. Tangential section of the secondary xylem of C. whiteana. Xl75. Note uniand biseriate rays. Details: p, pore; perforation plate; pc, perforated ray cell; pi, pits; r, ray; s, septate fiber-tracheid. pp,

PAGE 142

126

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127 Argophyllum J. R. & G. Forst. Introduction The genus Argophyllum was described by J. R. and G. Forster in 1776 from specimens of~ nitidum, a species which occurs in both New Caledonia and eastern Australia (Forster and Forster, 1776; Zemann, 1907). The generic name refers to the silvery-white color of the lower surface of the leaves of these plants (Bailey, 1900; Forster and Forster, 1776). Argophyllum contains nine other species besides the type, with three species endemic to eastern Australia and six to New Caledonia (Zernann, 1907). Plants of Argophyllum are shrubs or small trees that bear alter nate, exstipulate leaves. The flowers are mostly five rnerous, rarely six-merous, and arranged in panicules or corymbs. Each flower contains a twoto five-celled, half inferior ovary which is adnate to the calyx tube and ripens into a capsule (Bailey, 1900; Bentham, 1864; Zernann, 1907). Zemann (1907) divided Argophyllum into two sections. The section Brachycalyx contains species with a calyx that is much shorter than the corolla, while species in section Dolichocalyx have a calyx at least half as long as the corolla. Argophyllum ellipticum is endemic to humid, moun tainous areas in the northern portion of New Caledonia (Zemann, 1907). Argophyllum cryptophlebum is restricted to

PAGE 144

128 the mountains in northern Queensland, Australia, and~ nullumense is endemic to the mountains of northern New South Wales, Australia (Bailey, 1900; Zemann, 1907). Most taxonomists agree that Argophyllum belongs in either the subfamily Escallonioideae of the Saxifragaceae (Engler, 1890, 1928; Schulze-Menz 1964; Thorne, 1976, 1983) or the Escalloniaceae (Airy Shaw [in Willis, 1973]; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966, 1980). Cron quist (1968, 1981), however, placed this genus in his Gros sulariaceae. Although most of these taxonomists agree that Argophyllum belongs in the Rosales or some roughly equiva lent taxon, Dahlgren (1975, 1980, 1983) has placed this genus in his Cornales. Wood of A. cryptophlebum, nullumense, and A. ellipticum, and leaves and nodes of the first two species were available for this study (Table 2). All three species are included in the section Brachycalyx. Unless noted otherwise, data apply to all species examined. Observations Leaves of~ cryptophlebum are simple and ovate with tiny serrations, while the leaves of A. nullumense are simple and elliptic with very widely-spaced, and relatively large serrations. Both species have alternate leaves. Ve nation is semicraspedodromous with a prominent midvein and conspicuous secondary veins whose branches extend near the leaf margin and arch distally to join with superadjacent secondary or tertiary veins (Fig. 110). Areole development

PAGE 145

129 is imperfect, and veinlets may be straight, curved, or branched one to three times (Fig. 111). The tapered or blunt vein endings are composed of two to seven helically thickened tracheids that are usually elongate, but may be short and irregularly-shaped. Some of these cells also possess short protuberances on their lateral walls. The nodal pattern is trilacunar, three-trace, and three collateral bundles enter a petiole (Fig. 112). These three bundles fuse laterally approximately midway along the length of a petiole to form a larg e , horseshoe-shaped bundle in the center of a petiole (Fig. 112). In A. nullumense the ends of this petiolar bundle inroll or invaginate, while the ends of the petiolar bundle in A. cryptophlebum do not (Fig. 112). The horseshoe-shaped bundle enters the lamina distally. Leaves of~ cryptophlebum and A. nullumense are dorsi ventral with a poorly differentiated palisade layer and a spongy mesophyll layer with relatively small intercellular spaces (Fig. 113). In transection cells of the palisade layer are square or oval, closely appressed, and usually stain very darkly. Often these cells contain tan or brown deposits (Fig. 113). The leaves of A. nullumense have a unior biseriate palisade cell layer while those of A. cryptophlebum have a biseriate palisade layer. The cells of the spongy mesophyll have various shapes and sizes, although many of them are elongate periclinally in transection (Figs. 113 & 115).

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130 The midvein of A. nullumens e is a co nce ntric, m ed u lated bundle with x y lem internal to the p hlo em (Fig. 114 ) . This bundle is surrounded by a parenchymatous bundle sheath with bundle sheath extensions of thick-walled, unlignified parenchyma cells both abaxially and adaxially. The midvein of~ cryptophlebum is an arc-sha p ed, collateral bundle. This bundle is also surround e d b y a parenchymato u s bundle sheath, however, the bundle sheath extensions are composed of thin-walled parenchyma cells adaxially and thinand thick-walled, unlignified parench y ma cells and collenchyma cells abaxially. Although some of the smaller vascular bundles (secondary veins) of A. nullumense may be amphi cribral (Fig. 114), these bundles commonly are collateral. All the smaller bundles of A. cryptophlebum are collateral. In both species these smaller bundles (secondary and minor veins) lack both bundle sheaths and bundle sheath extensions. The epidermal layers are uniseriate and contain cells that are rectangular with rounded corners, or oval in tran section (Fig. 113). In surface view the epidermal cells of Argophyllum lea v es are variously-shaped and may possess curved or sinuous (~ cryptophlebum), or straight (~ nullumense) anticlinal walls. The cuticle is very thin (<5 um) in both species. Abundant stomata are restricted to the abaxial epider mis, and the stomatal apparatus is anomocytic. In surface view individual guard cells are reniform and guard-cell pairs are almost circular in outline. Guard-cell pairs have

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131 an average le n gth of 19 u m a n d a width of 18 u m (length / width ratio 1.06). In tra n s e ction g u ard c e lls are o v al, and each cell bears a very small cuticular horn that represents the outer ledg e ov e rarch i ng a st om a. In addition, the guard cells are raised above th e le v el of th e abaxial epidermis by cur v ed or L-shaped s u bsidary c e lls (Fig. 115). Multicellu lar, T-shaped trichomes with one to two stalk cells and an elongate, lignified t e rminal cell are abundant over the abaxial leaf surface (Figs. 113 & 115). The stalk cells are thin-walled and contain cyto p lasm and a large nucleus. The terminal cell is thick-walled, lignified and devoid of pro toplasm. The terminal cell and the uppermost stalk cell are separated by walls that possess elongate pits (Fig. 116). Although the marginal teeth of~ cryptophlebum and~ nullumense have the tumid appearance of hydathodes, water pores are not visible in the adaxial epidermis of these serrations. A prominent vein flares as it terminates in each tooth (Fig. 117). In cleared leaves certain marginal teeth possess cells that stain more darkly than the other surrounding cells of the tooth. This darker staining may indicate that these cells are glandular. The wood of the three species of Argophyllum studied is very similar with respect to cell types, vessel element morpholog y , most cell dimensions and composition of ray tissue. Ne v ertheless, some m inor differences do occur among these species with regard to pore diameter, length of imperforate elements and size of the xyle m rays. These

PAGE 148

132 differenc e s gen e rall y pa rallel the distribution of the three species. Based upon wood anato my the two Australian species, cryptophlebum and~ nullumense, are similar, while the New Caledonian species, ellipticum, is different from them. Axial parenchyma is absent from all three species. Weakly discernible growth rings are present in wood of A. nullumense, while distinct growth rings are present in A. cryptophlebum. Growth rings are absent in~ ellipticum. The former two species are diffuse porous, and all three species ha ve fine-textured wood with very numerous, angular pores per square mm (range 55-205/mm 2 , x= 129). Although pores are predominantly solitary for all species (64%), true radial multiples of two to seven cells (22%) and clusters of two to nine cells (14%) are not uncommon (Fig. 118). Approximately one third of the pore clusters observed are due to overlapping end walls of vessel elements. Pore diameters are very small for all three species (range 27-61 um, x= 41), however, the Australian species, crypto phlebum and~ nullumense, have narrower pores (range 27-48 um, x= 37) than the New Caledonian species,~ ellipticum (range 36-61 um, x= 49). Vessel walls are thinner in A. cryptophlebum and~ ellipticum (range 1-3.2 um, x= 2.4) than in~ nullumense (range 3.2-5.3 um, x= 3.5). Vessel elements are shortest in A. nullumense (range 517-1050 um, x= 755), slightly longer in~ ellipticum (range 550-1217 um, x= 894), and longest in~ cryptophlebum (range 500-1400 um, x= 1020). Fine spiral thickenings may be present in vessel elements of all three species. Perforation plates are

PAGE 149

133 exclusively scalariform on oblique end walls with 6-25 thin bars per plate (x= 15) (Fig. 119). Rarely perforation plates are compound _ with two scalariform perforation plates per oblique end wall. The thin bars may be forked or branched. Perforations typically lack a border, however, complete borders occasionally are present around perfora tions in~ cryptophlebum. End-wall angles range from 0-21 (x= 10). Oval to elongate intervascular pits are usually alternate, but transitional and opposite arrangements may occur (Fig. 119). These pits have minute diameters (range 2.1-3.2 um, x= 2.8). Imperforate tracheary elements are septate fibers with non-bordered, slit-like pits in both A. cryptophlebum and A. nullumense. Argophyllum ellipticum possesses septate fiber tracheids with pits characterized by a small, circular bor der and inner apertures that extend well beyond the margin of the pit border (Fig. 119). Most imperforate elements have medium length, although the septate fibers of A. cryptophlebum and~ nullumense are shorter (range 850-1817 um, x= 1170) than the septate fiber-tracheids of~ ellipti cum (range 900-1667 um, x= 1317). All imperforate elements have thick walls (range 2.6-10.5 um, x= 5.2 um). The ray system of Argophyllum is predominantly composed of homocellular, uniseriate rays of upright cells and heter ocellular, bito multiseriate rays (Fig. 120). Homocellu lar, biseriate and heterocellular, uniseriate rays rarely occur. Uniseriate rays range in height from 1-24 cells

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134 (.08-2.52 mm), while biand multiseriate rays range in height from 6-51 cells (.43-3.20 mm) and in width from 2-6 cells (23-78 um). The heterocellular rays of A. ellipticum are generally wider (3-6 cells) than those of A. crypto phlebum and A. nullumense (2-4 cells). Perforated ray cells with scalariform perforation plates are infrequent in the heterocellular rays of A. nullumense and~ ellipticum (Fig. 121), but are lacking in~ cryptophlebum. Sheath cells are absent from all three species. No ergastic substances are present in the ray tissue. Although vessel to ray paren chyma pitting may be transitional, it is mostly opposite or alternate. All types of rays may be joined end-to-end, and multiseriate rays are commonly split by vessels or imper forate tracheary elements.

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Figure 110. Leaf of Argophyllum cryptophlebum showing marginal serrations and semicraspedodromous venation. Xl. Figure 111. Vein ending of~ nullumense. Xl75. Figure 112. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of~ nullumense. XlO. Details: t, tracheids.

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1 3 6 a b C d 112

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Figure 113. Transverse section of a leaf of Argophyllum nullumense. X437. Note poorly differentiated biseriate palisade layer and T-shaped trichome. Figure 114. Transverse section of the midvein of a leaf of A. nullumense. X46. Note secondary vein. Figure 115. Transverse section of the abaxial epidermis of a leaf of A. nullumense. X700. Figure 116. Surface view of the pitting between the terminal cell and uppermost stalk cell of a T-shaped trichome of~ cryptophlebum. Xl750. Figure 117. Marginal serration of a leaf of A. cryptophlebum. Xll O. Details: ab, abaxial epidermis; ad, adaxial epidermis; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; gc, guard cell; pi, pits; pl, palisade layer; sl, spongy mesophyll layer; tr, tri chome; sv, secondary vein; vb, vascular bundle.

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138 114 gc ........, " c?fy I -115~ tr

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Figure 118. Transverse section of the secondary xylem of Argophyllum nullumense showing both solitary and radial multiples of pores. XllO. Figure 119. ellipticum. Radial section of the secondary xylem of A. X437. Note septa (arrows) of septate fibers. Figure 120. ellipticum. Tangential section of the secondary xylem of A. XllO. Note uniand multiseriate rays. Figure 121. Radial section of the secondary xylem of A. ellipticum. X315. Note perforated ray cell with scalariform perforation plate. Details: p, pore; perforation plate; pc, perforated ray cell; pi, pits; r, ray; s, septate fiber. pp,

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140

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141 Donatia J. R. & G. Forst. Introduction The genus Donatia was described in 1 776 by J. R. and G. Forster based upon specimens of .!2.:_ fascicularis collected in Tierra del Fuego. The generic name commemorates the Italian naturaist Vitalianus Donati (Forster and Forster, 1776). The only other species in this genus, D. novae-zelandiae, occurs in alpine areas of New Zealand and Tasmania (Allan, 1961; Bentham, 1864; Cheeseman, 1925; Curtis, 1963). The cushion or mat plants of Donatia are erect, perennial herbs which are densely covered with sessile, exstipulate, simple leaves (Allan, 1961; Bentham, 1864; Cheeseman, 1925; Curtis, 1963). The terminal or axillary, solitary flowers have five to seven sepals, five to ten petals, and two to three stamens which are inserted on a disc. The twoto three-celled, inferior ovary ripens into a capsule. Hooker (1865) placed Donatia in the Saxifragaceae with in the tribe Saxifrageae. Although Engler (1890) initially placed this genus in the rosalian Saxifragaceae within its own subfamily Donatioideae, he later was uncertain about its placement (Engler, 1928). Other workers have placed Donatia within the Stylidiaceae, in its own subfamily, the Donati oideae (Dahlgren, 1975, 1980, 1983; Mildbraed, 1908; Muel ler, 1879; Thorne, 1976; Wagenitz, 1964). Some systema tists have elevated this subfamily to form the monogeneric family Donatiaceae (Airy Shaw in Willis, 1973; Cronquist,

PAGE 158

142 1981; Skott sbe rg, 1915; Tak h tajan, 19 80 , 1983). Most of these workers have p laced Donatia in the order Campanulales. Thorne (1976, 1983), however, includ e d it in the Rosales and Dahlgren (1975, 1980, 1983) placed it in his Cornales. The following observations are based upon a specimen of D. novae-zelandiae (Table 2). Observations Donatia novae-zelandiae possesses very small, entire, lanceolate leaves. These sessile, exstipulate leaves are spirally arranged and completely enclose the stem. Venation is perfectly developed, suprabasal acrodromous with a promi nent midvein and two conspicuous secondary veins that di verge distally to the base of the lamina and extend to the leaf apex (Figs. 122 & 123). In the larger leaves two very small tertiary veins may diverge from one or both of the secondary veins. Vein areole development is lacking. Terminal vein endings taper and are composed of one or two helically thickened, elongate tracheids. The nodal pattern is unilacunar, one-trace, and a single vascular bundle enters the base of a sessile lamina (Fig. 124). The leaves are isobilateral with an undifferentiated rnesophyll throughout most of a lamina (Fig. 125). A poorly differentiated, biseriate palisade layer composed of loosely arranged, elongate cells occurs only near the apex of a leaf (Fig. 126). Both the spongy mesophyll cells and undiffer entiated mesophyll cells have various shapes and sizes and

PAGE 159

143 are se p arated b y num e rou s , large int e rcel lular spaces. Crystals are abs e nt in Donatia leaves. In transection a very s m all midvein occurs in the basal third of a leaf. In the distal two thirds of a leaf the midvein and two, three or more bundles (secondary and ter tiary veins) occur, depending upon whether or not tertiary veins ha v e diverged from the secondary veins (Fig. 125). Each bundle possesses three to seven tracheids, while phloem is not distinguishable in any bundle. All bundles are surrounded by a bundle sheath composed of parenchyma cells which are smaller and more compactly arranged than the surrounding mesophyll cells. No bundle sheath extensions occur. In the distal two thirds of most leaves a large, round or oval mass of lignified parenchyma tissue occurs abaxial to the midvein and smaller vascular bundles (second ary veins) (Fig. 125). This lignified parenchyma tissue is composed of thick-walled, elongate cells filled with a tan, densely staining, amorphous substance that is arranged con centrically in the cell lumen (Fig. 127). Both epidermal layers are uniseriate and composed of periclinally flattened cells of various shapes and sizes in transection (Fig. 125 & 126). In surface view the epidermal cells are rectangular or trapezoidal with the long axis of a cell oriented parallel to the long axis of a leaf (Fig. 128). The cuticle overlying both epidermal layers is very thick (>7 um). Numerous stomata occur in both epidermal layers, and the stomatal apparatus is paracytic (Fig. 128). The two

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144 elongate subs idary cells often a re very similar to the other epidermal c e lls and do not completely envelop the guard cells. In surface view guard cells are reniform and guard cell pairs are elliptic in outline with an average length of 44 um and a width of 30 um (length / width ratio 1.47). In transection guard cells ar e oval to irregular in shape, and each cell bears a small, thin cuticular horn internally and a large, thick cuticular horn externally that represent the inner and outer ledges, respectively, overarching a stoma (Fig. 129). Although foliar trichomes are absent, multicel lular, uniseriate trichomes are abundant on the stem, especially in the axils of the leaves. The cells of these trichomes are separated by oblique septa that bear numerous small perforations or pit-like structures (Fig. 130). The basal cell of a trichome is filled with dense, darkly stain ing, granular cytoplasm, while the other cells are empty. The terminal cell of a trichome is tapered. Hydathodes are absent in D. novae-zelandiae. Dark brown fungal hyphae typically occur intermingled with the uniseriate trichomes and on the surface of the leaves. Since D. novae-zelandiae is a herbaceous, perennial plant that produces a very small amount of secondary xylem, no measurements were made of this tissue. The wood of D. novae-zelandiae possesses angular pores with very small diameters (Fig. 131). These pores may be solitary, but more commonly are clustered. Vessel elements are connected by scalariform perforation plates and scalariform to

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145 transitional intervascular pitting (Fig. 132). A few thick walled fibers with simple pits also occur in the secondary xylem. Axial parenchyma is abundant, but arranged in no definite pattern. Spiral thickenings are absent from the vessel elements and fibers. No xylem ray system is visible.

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I I Figure 122. Leaves of Donatia novae-zelandiae showing en tire margins and perfectly developed, suprabasal acrodromous venation. XlO. Note diagrammatic representation showing presence or absence of lignified parenchyma (lp) in association with the veins. Figure 123. Portion of a lamina of D. novae-zelandiae. X46. Figure 124. Unilacunar, one-trace nodal pattern of D. novae-zelandiae. X46. Figure 125. Transverse section of a leaf of D. novae zelandiae. Xl75. Note undifferentiated mesophyll and lignified parenchyma cells abaxial to vascular bundles. Figure 126. Portion of lamina of D. novae-zelandiae proximal to the leaf apex. Xl75. Note poorly differentiated biseriate palisade layer. Details: ab, abaxial epidermis; ad, adaxial epidermis; c, cuticle; lp, lignified parenchyma; lt, leaf trace; m, mesophyll; pl, palisade layer; sl, spongy mesophyll layer; v, vein with lignified parenchyma cells; vb, vascular bundle.

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147 Ip 122 125 126

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Figure 127. Transection of lignified parenchyma cells abaxial to vascular bundles in leaves of Donatia novae zelandiae. Xl750. Figure 128. Paradermal section of a leaf of D. novae zelandiae. X437. Note paracytic stomatal apparatus. Figure 129. Transverse section of the abaxial epidermis of a leaf of D. novae-zelandiae. X700. Figure 130. Oblique septum of a multicellular, uniseriate trichome of D. novae-zelandiae. X700. Figure 131. Transverse section of a stem of D. novae zelandiae. Xll0. Note small amount of secondary xylem. Figure 132. Radial section of the secondary xylem of !2.:_ novae-zelandiae. X437. Details: ab, abaxial epidermis; c, cuticle; f, fibers; gc, guard cells; i, inner ledges; o, outer ledges; p, pore; pi, pits; pp, perforation plate; se, septum; st, stoma; x, secondary xylem.

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1 49

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150 Anodopetalum A. Cunn. Introduction The monotypic genus Anodopetalum was described by Allan Cunningham in 1839 (Bentham, 1864; Burbidge, 1963). Anodo petalum biglandulosum is endemic to wet lowland and subal pine areas of the southeast, southwest and west floristic zones of Tasmania (Beadle, 1981; Bentham, 1864; Mosley, 1974b). Plants of Anodopetalum are tall shrubs or trees with narrow-oblong, simple, opposite leaves and deciduous, interpetiolar stipules (Bentham, 1864). Flowers usually occur singly in the axils of the upper leaves, and each flower possesses a fouror five-merous perianth, twice as many stamens as petals and a superior ovary that ripens into a one-seeded berry (Bentham, 1864). Anodopetalum biglandu losum often forms monospecific stands owing to its peculiar growth habit whereby stems bend over to a horizontal posi tion after growing a few meters (Beadle, 1981). Branches develop and grow upward from the nodes of these bent stems which remain more or less horizontal and continue to grow in diameter. Because of this unusual growth habit,~ bigland ulosum forms impenetrable woodland thickets called "horizontal," in reference to the same common name of the species (Beadle, 1981). Virtually all taxonomists include Anodopetalum in the Cunoniaceae within the Rosales or some other equivalent order (Airy Shaw in Willis, 1973; Cronquist, 1968, 1981;

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151 Da h 1 gr en , 1 9 7 5 , 1 9 8 0 , 1 9 8 3 ; Eng 1 er , 1 8 9 0 , 1 9 2 8 ; Hutchinson, 1967; Schulze-M e nz, 1964; Takhtajan, 1966, 1980, 1983; Thorne, 1976, 1983). Observations Anodopetalum possesses opposite, narrow-elliptic leaves that bear rounded, wid e ly spaced crenations. Venation is semicraspedodromous with a prominent midrib and conspicuous secondary veins that extend near the leaf margin and arch distally to join with the superadjacent secondary veins (Fig. 133). Vein areole development is imperfect. Veinlets may be straight, but are more commonly branched one to four times (Fig. 134). Vein endings are composed of helically thickened tracheids and parench y rnatous bundle sheath cells with thick, primary cell walls (Fig. 134). These tracheids, which may be elongate, curved, forked, or clavate, often possess protuberances at the junction between two paren chymatous bundle sheath cells. The nodal pattern is trilacunar, three-trace (Fig. 135) . Each of the lateral traces divides to form several additional lateral traces. The median leaf trace and two lateral traces enter a petiole, while the other resultant lateral traces enter an interpetiolar stipule. Thus one median and two lateral bundles enter the base of a petiole (Fig. 135). Distally to the base of a petiole two very small bundles become visible in the ground tissue near the primary xylem of the two lateral bundles. The origin of these two small bundles is unclear. In one specimen, one of

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152 these small bundles arose from one of the lateral petiolar bundles while the other arose from the median bundle. Dis tally in a petiole the three bundles which entered the petiole from the stem, fuse laterally to form a large, arc shaped collateral bundle (xylem adaxial) in the center of the petiole (Fig. 135). The two small bundles also enlarge and fuse to form a small, inverted (xylem abaxial), dorsally flattened, collateral bundle adaxial to the large central bundle (Fig. 135). These two opposing bundles enter the lamina distally (Fig. 135). Leaves of Anodopetalum are dorsiventral with a rela tively narrow, biseriate palisade layer and a much wider, lacunose spongy mesophyll layer (Fig. 136). The palisade layer possesses larger, oval to rectangular cells in its uppermost layer and smaller, elongate or columnar cells in its lower layer (Fig. 136). These two types of cells may be interspersed with one another throughout the palisade meso phyll. The spongy mesophyll has cells of various shapes and sizes separated by numerous, large intercellular spaces (Fig. 136). Occasionally druses and rarely prismatic crystals occur in the spongy mesophyll cells. The midvein of Anodopetalum leaves is composed of two opposing collateral bundles (Fig. 137). Both bundles are surrounded by a bundle sheath of lignified parenchyma cells and have sclerenchyma fibers adjacent to the primary phloem. Bundle sheath extensions composed of lignified parenchyma cells and collenchyma cells also occur both abaxially and

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153 adaxially. The smaller, collateral bundles (secondary and minor veins) possess a bundle sheath of thick-walled, unlignified parenchyma cells without bundle sheath extensions (Fig. 136). Both epidermal layers are uniseriate and typically consist of square to rectangular cells in transection (Fig. 136). In surface view the epidermal cells are square to polyhedral with mostly straight, rarely curved, anticlinal walls. The cuticle is thick and undulate (>5 um). Anodo petalum leaves typically lack trichomes, however, a few elongate, thick-walled, bulbous-based trichomes with tapered ends may occur adaxially at the base of a petiole. Numerous stomata are restricted to the abaxial epider mis, and the stomatal apparatus is anomocytic. In surface view the guard cells are oval to reniform. Guard-cell pairs are virtually circular in outline with an average length of 30 um and a width of 29 um (length/width ratio 1.03). In transection the guard cells are oval, and each cell has a cuticle over its outer wall. Some guard cells bear a very small cuticular protuberance that represents the outer ledge overarching the stoma. The blunt, marginal crenations and the leaf apex con tain glandular tissue characterized by thick-walled, unlig nified parenchyma cells with very dense, darkly staining cytoplasm (Fig. 138). Each crenation is supplied by an arc of vascular tissue that is derived from the union of two secondary or tertiary veins.

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154 The wood of Anodopetalum exhibits disti n ct growth rings and is diffuse porous. The wood is fine-textured with ver y numerous pores (range 190-370 / rnrn 2 , x= 277) that are mostly angular, but may be circular, in outline. The pores have very small tangential diameters (range 18-44 um, x= 33) and thin radial walls (range 1.6-4.2 urn, x= 2.8). The pores are usually solitary (54 % ) or in true clusters of two to se v en cells (44 % ), although true radial multiples of two to four cells (2%) do occur (Fig. 139). Vessel elements have medium length (range 410-891 urn, x= 638) and possess oblique end walls with angles ranging from 17-38 (x= 26). These cells lack spiral thickenings. Perforation plates are mostly simple, although a few are scalariform with 3-11 thin bars (x= 8) per plate (Fig. 140). The simple perforations have complete borders, while the perforations in the scalariforrn perforation plates lack borders. Intervascular pitting is mostly scalariforrn, although transitional and opposite arrangements also occur (Fig. 140). These elongate to oval pits have small diameters (range 4.7-7.4 um, x= 5.5). Tracheids with circular-bordered pits and oval inner apertures that extend slightly beyond the pit border also occur (Fig. 141). The diameter of these pits is similar to that of the intervascular pits. Tracheids have moderately short to medium length (range 670-1170 urn, x= 971), rela tively thin walls (range 2.6-5.3 urn, x= 3.8) and fine spiral thickenings. Some vessel elements and tracheids also con tain brown, amorphous contents.

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I 15 5 Axial parenchyma is common and is eith e r apotracheal diffuse-in-aggregates with short tangential, uniseriate bands of four to five cells, or marginal at the end of a growth ring (Fig. 139). Very rarely paratracheal scanty parenchyma occurs. Axial parenchyma cells contain abundant dark brown deposits and starch grains (Fig. 139). Vessel to axial parenchyma pitting is scalariform. Although the xylem ray system predominantly is composed of homocellular, uniand biseriate rays of upright cells, heterocellular, uniand biseriate rays may also occur (Fig. 141). All rays are relatively short, with heights ranging from 1-24 cells (.08-.52 mm) for uniseriate rays and 8-24 cells (.17-.58 mm) for biseriate rays. Biseriate ray width ranges from 18-23 um. Dark brown deposits which are similar to those in the axial xylem parenchyma cells also are abun dant in ray parenchyma cells. Perforated ray cells and sheath cells are absent. Vessel to axial parenchyma pitting is mostly scalariform, however, transitional patterns also occur. No fusion of rays is noted.

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Figure 133. Leaf of Anodopetalum biglandulosum showing marginal crenations and semicraspedodromous venation. X2. Figure 134. Vein ending of~ biglandulosum. Xl75. Figure 135. Transverse sections of a node (a) and proximal (b), median (c) and distal (d) sections of a petiole of~ biglandulosum. XSO. Details: b, bundle sheath; t, tracheid.

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157 133

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Figure 136. Transverse section of a leaf of Anodopetalurn biglandulosurn. Xl75. Figure 137. Transverse section of a midvein of a leaf of A. biglandulosum. Xl 75. Figure 138. Marginal crenation of a leaf of A. biglandulosum. XllO. Note the arc of vascular tissue which vascularizes the crenation. Figure 139. Transverse section of the secondary xylem of A. biglandulosurn. Xl75. Note clustered and solitary pores. Figure 140. Radial section of the secondary xylem of A. biglandulosum. Xl 75. Figure 141. Tangential section of the secondary xylem of A. biglandulosum. Xl 75. Details: ab, abaxial epidermis; ad, adaxial epidermis; ap, axial parenchyma; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; f, fibers; g, gland; p, pore; pi, pits; pl, palisade layer; pp, perforation plate; r, ray; sl, spongy mesophyll layer; t, tracheid; vb, vascular bundle; vt, vascular tissue.

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160 Aphanopetalum Endl. Introduction The genus Aphanopetalum was described in 1839 by S. L. Endlicher based upon specimens of~ resinosum (Bailey, 1900; Bentham, 1864; Burbidge, 1963). The generic name refers to the obscure petals of the flowers (Bailey, 1900). Aphanopetalum contains two species that are endemic to Aus tralia. Aphanopetalum resinosum is found in rainforests of eastern Australia from southeastern Queensland to southern New South Wales (Beadle, 1981; Burbidge, 1963). The other species, !::.:.._ occidentale, is restricted to Western Australia (Bentham, 1864; Burbidge, 1963). Plants of A. resinosum are scrambling or viny shrubs with opposite, serrate to entire leaves that either possess minute stipules or are exstipulate (Bailey, 1900; Bentham, 1864). The flowers have four sepals and eight stamens, while the petals are minute or absent. Each flower has a four-celled, superior ovary that ripens into a hard, indehiscent, nut-like fruit (Bailey, 1900; Bentham, 1864; Engler, 1928). Systematists typically have placed Aphanopetalum in the Cunoniaceae within the orders Rosales (Engler, 1928; Thorne, 1983), Saxifragales (Takhtajan, 1980, 1983), Grossu lariales (Cronquist, 1981) or Cunoniales (Dahlgren, 1975, 1980, 1983; Hutchinson, 1967). However, recent studies by Dickison (1975c, 1980b) have cast doubt on the cunoniaceous affinity of this genus.

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161 Onl y leafy stems of A. resinosum were available for this study (Table 2). Observations Aphanopetalum resinosum possesses elliptic, serrate, opposite leaves (Fig. 142). The marginal serrations are very small and rounded or acute. L e aves also ha v e two minute, avascular, acicular stipules on each side of the petiole base (Fig. 143). The stipules are composed of cells filled with densel y staining cytoplasm and appear glandular (Fig. 144). The stipules are morphologically and anato m cally similar to the marginal serrations of the leaves. Venation is semicraspedodromous with a prominent midrib and conspicuous secondary veins whose branches arch distally to join with superadjacent secondaries and terminate in the marginal teeth (Fig. 142). Veinlets may be straight, curved or branched (Fig. 145). Terminal vein endings taper and are composed of three to four helically thickened, elongate tracheids. The nodal pattern is unilacunar, one-trace. Two small traces, however, separate from this leaf trace shortly after it diverges from the stem vasculature (Fig. 146). Thus a large, central, flattened bundle and two small, lateral, round bundles enter the base of a petiole (Fig. 146). These three collateral bundles extend the length of a petiole and enter the lamina distally. Leaves of A. resinosum are dorsiventral with a well differentiated, biseriate palisade la y er and a lacunose

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162 spongy mesophyll layer (Fig. 147). The cells of the pali sade layer are columnar and tightly appressed. The cells of the spongy mesophyll layer are variously shaped and sepa rated by numerous small intercellular spaces. Frequently the cells of both layers contain darkly staining cytoplasm due to tan or brown deposits. No crystals occur in the palisade or spongy mesophyll cells. The midvein of a leaf is a flattened collateral bundle surrounded by a bundle sheath composed of thick-walled fi bers, thick-walled, lignified parenchyma cells and thin walled parenchyma cells (Fig. 148). Bundle sheath exten sions of thick-walled, unlignified parenchyma cells and collenchyma cells occur both adaxially and abaxially. Druses are present in a few of these parenchyma cells locat ed abaxial to the midvein. The smaller bundles of a leaf (secondary and minor veins) are round collateral bundles surrounded by a bundle sheath composed of thin-walled paren chyma cells (Fig. 147). These smaller bundles lack bundle sheath extensions. Both epidermal layers are uniseriate. In transection the adaxial epidermal cells are typically oval or round, while the abaxial epidermal cells are more flattened and elongate or elliptic. In surface view the epidermal cells are variously shaped with sinuous to curved anticlinal walls. The cuticle is thick (>5 um) and trichomes are absent. Stomata are restricted to the abaxial epidermis, and the stomatal apparatus is anomocytic. In surface view guard cells are reniform, and guard-cell pairs are circular

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163 to elliptic in outline. Guard-c e ll pairs ha ve an average length of 25 um and a width of 19 um (length / width ratio 1.32). In transection the guard cells are oval to rectangu lar and thick-walled, and each cell bears a short, thin cuticular horn that represents the outer ledge overarching a stoma. The marginal leaf teeth of A. resinosum are composed of cells filled with densely staining cytoplasm. In cleared leaves the apical cells of a tooth stain lighter than sur rounding cells which may indicate thinner cell walls. A large vein flares as it terminates in each tooth (Fig. 149).

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Figure 142. Leaf of Aphanopetalum resinosum showing small marginal serrations and semicraspedodromous venation. Xl. Figure 143. Transverse section of stem and petiole of A. resinosum. X46. Note the two stipules on either side of the petiole base. X46. Figure 144. Transverse section of the avascular stipules of A. resinosum. Xl 7 5. Figure 145. Vein ending of A. resinosum. Xl75. Details: pe, petiole; tracheid. s, stipules; se, stem; t,

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165 s 142 143

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Figure 146. Transverse sections of a node (a) and proximal (b) and distal (c) sections of a petiole of Aphanopetalum resinosum. X30. Figure 147. Xl75. Transverse section of a leaf of A. resinosum. Figure 148. Transverse section of a midvein of a leaf of A. resinosum. Xl 10. Figure 149. Xl75. Marginal serration of a leaf of A. resinosum. Details: ab, abaxial epidermis; ad, adaxial epidermis; b, bundle sheath; be, abaxial bundle sheath extension; be', adaxial bundle sheath extension; c, cuticle; f, fibers; pl, palisade layer; sl, spongy mesophyll layer; vb, vascular bundle.

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167 147 a 0 b C 146 149

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DISCUSSION Anatomy of Twelve Australasian Genera Despite the morphological and anatomical heterogeneity of the Saxifragaceae, sensu lato, recent work on the vegeta tive anatomy of the woody members of the group (Ramamon jiarisoa, 1980; Stern, 1974a, 1978b; Styer and Stern, 1979a, 1979b) has revealed certain anatomical similarities in the wood and leaves of the genera studied. Specifically there appear to be at least eleven anatomical features in a hypothetical archetypical woody saxifrage (Stern, pers. comm.). A list of these eleven anatomical features and their presence or absence for the genera in this study is provided (Table 3). The presence of all or most of these anatomical features poses a strong probability of saxifraga ceous affinity for a given genus. Aphanopetalurn is not included in Table 3 because wood was unavailable for study. Although certain anatomical characteristics are pecu liar to each of the twelve Australasian genera in this study, other features are fairly constant throughout these plants. While most genera have alternate, dorsiventral, exstipulate leaves, Bauera, Anodopetalurn and Aphanopetalum have opposite, stipulate leaves. Only Donatia has isobi lateral leaves. Most genera possess sernicraspedodrornous venation, although Bauera and Corokia also possess brochido dromous venation. Tetracarpaea and Donatia, however, are 168

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Table 3 . Anatomical features of eleven Australasian woody saxifragaceous g e n e ra: +, always present; ( +) , usually present; , always absent; ( ) , usually abs e nt. GENERAa ---Tet Bau Ixe Anp Cut Abr Car Co r Arg Don And ANATOMICAL FEATURE Predominantly solitary pores + + + + + + + + + Scalariform perforation plates + ( ) + + + + + + + + ( ) Scalariform, transitional, opposit e intervascular pitting + + ( ) + + + + ( + ) ( + ) + + Axial xylem parenchyma sparse or abs e nt ( +) + + + + + + + + + Tr ache ids or tracheids and fiber-trach eids + + + + + + + ( +) + Spiral thickenings in trachear y e lements + + + + + + + + + + Homocellular, uniseriate/ heteocellular, multiseriate rays + + + + + + + + + Perforated ray cells + + + + + + + ( + ) ( + ) Unicellular, bulbous-based foliar trichomes + + + + ( ) Hydathodes/Glands + + + + + + ( ) ( ) + Trilacunar, 3-trace nodes + + + + + ( +) ( +) + O'I I..O aAbr, Abro2hyllum; And, Anodo2etalum; Anp, Ano2terus; Arg, ArgoQhyllum; Bau, Bauera; Car, Car2odetus; Cor, Corokia; Cut, Cuttsia; Don, Donatia; Ixe, Ixerba; Tet, Tetracar2aea.

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170 distinctive because the former has simple craspedodromous venation while the latter has acrodromous venation. The vein endings of most genera consist of elongate, helically thickened tracheids, although the vein endings of Tetracar paea and Ixerba also possess fiber-tracheids and fibers, respectively. The vein endings of Bauera also exhibit short, wide tracheids. The nodal pattern in the genera studied is either unilacunar, one-trace (Tetracarpaea, Bauera, Donatia, Aphan opetalum and one species of Corokia) or trilacunar, three trace (Ixerba, Anopterus, Cuttsia, Abrophyllum, Carpodetus, Argophyllum, Anodopetalum and two species of Corokia). A pentalacunar, five-trace nodal pattern previously had been reported for a species of Argophyllum (Swamy, 1954). The epidermides of the leaves are typically uniseriate among these genera, although Bauera, Cuttsia and Carpodetus possess a biseriate adaxial epidermis. All twelve genera typically possess stomata in the abaxial epidermis, and the stomata} apparatus is anomocytic. Only Donatia has stomata in both epidermides and a paracytic stomata} apparatus. Donatia also is the only genus with both inner and outer cuticular ledges overarching a stoma. The other genera possess only an outer cuticular ledge overarching a stoma. The palisade layer is typically well differentiated and may be uni-, bior triseriate in the genera studied, al though Argophyllum and Corokia have a relatively poorly differentiated palisade layer. The spongy mesophyll is

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1 71 usually lac u nos e , altho u gh it i s c omp act in Carpodet u s and Argophyllum. Bundle sheaths composed of thinor thick-walled paren chyma cells are common in all gen e ra except Tetracarpaea and Bauera. Crystals occur in the leaves of all genera except Corokia, Argophyllum and Donatia. Altho u gh druses are the most comnon type of crystal in the leaves of these genera, Bauera possesses prismatic crystals, Cuttsia and Abrophyllum possess crystal sand and Ixerba possesses distinctive crystalloids. In those genera with growth rings, the wood is typical ly diffuse porous with very numerous, predominantly soli tary, angular pores with small diameters. The wood of Bauera, however, may be ring porous, and the wood of Anop terus, Carpodetus, and Corokia may be semi-ring porous. Growth rings are present in the wood of genera which occur in temperate climates, but are absent in the wood of those from tropical environments. The vessel elements of most genera have medium to long length and oblique end walls with scalariform perforation plates. Vessel elements of Bauera and Anodopetalum, however, possess predominantly simple perforation plates. Intervascular pitting is variable in most genera and may be scalariform, transitional, opposite or alternate. The pits are typically oval or elongate and have a minute to small diameter. Imperforate elements are typically tracheids, although Corokia and Argophyllum possess septate fiber-tracheids and

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172 s e ptate fib e rs. T h e imperforate cells typically have medium to long length, although Tetracarpaea and Bauera possess short trach e ids. Spiral thickenings are typically present in the imperforate el e ments and / or the vessel elements of all genera except Donatia. The axial parenchyma is sparse in most genera, although it may be abundant (Donatia and Anodopetalu m ) or absent (Corokia and Argophyllum). Axial parenchyma is typically apotracheal diffuse and diffuse-in-aggregates, although paratracheal scanty patterns rarely occur in Bauera, Ixerba, Anopterus, Abrophyllum and Carpodetus. Xylem ray tissue is typically composed of homocellular uniseriate rays of upright cells and heterocellular bito multiseriate rays. Cuttsia also has biseriate homocellular rays, while Bauera, Ixerba and Anopterus also have uniser iate heterocellular rays. Perforated ray cells occur in all genera except Anodopetalum and Donatia. Carpodetus is the only genus studied that exhibits prismatic crystals in ray parenchyma cells . Despite the similarities noted above, these genera are readily distinguishable from one another based upon various anatomical features. These distinctive anatomical charac teristics confirm certain taxonomic groupings, but also allow for some taxonomic rearrangements. In the systematic discussion that follows the classification system of Engler (1928) will be used throughout for purposes of convenience and understanding. Thus the subfamilies listed in Table 1

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173 will be mentioned repeatedly when taxonomic groupings and realignments among the genera in this study are discussed. Similar family names also will be used, however, because many workers have elevated Engler's subfamilies to family rank (Dahlgren, 1983; Takhtajan, 1983). Thus subfamily and family names sometimes will have to be used interchangeably when results and conclusions from these other studies are integrated with the present anatomical data. Unless noted otherwise, Engler's subfamilies (-oideae endings) are equivalent to the families (-aceae endings) mentioned. Relationships of Ixerba Ixerba has most of the anatomical characteristics of an archetypical woody saxifrage except for the lack of foliar trichomes and irregular pattern of intervascular pitting (Table 3). Although absent from the leaves, unicellular shaped trichomes occur on both the pedicels and flowers of Ixerba. These T-shaped trichomes were originally noted in Ixerba (Gardner, 1978), however, the exact location of this indument was not noted. These trichomes in Ixerba resemble the unicellular, T-shaped trichomes on pedicels and flowers of Kirengeshoma (Bensel and Palser, 1975b). Ixerba has solitary angular pores, and vessel elements with scalariform perforation plates with numerous bars per plate. Patel (1973b) studied the wood anatomy of Ixerba and also noted the above wood anatomical features. Ixerba also possesses diffuse and diffuse-in-aggregates apotracheal parenchyma, and scanty paratracheal parenchyrna. Besides

PAGE 190

174 th e se t ype s of a x ial parenchyma, Patel (1973b) noted vasi c e ntric parenchyma as w e ll. In the present study, very few intervascular pits were observed in Ixerba, and those pres ent were usually arranged in irregular uniseriate files (Fig. 24). Patel (1973b) found opposite to scalariform intervascular pitting in Ixerba. The infrequent and inter mittent upright cells along the margins of the few multi seriate wood rays of Ixerba are not sheath cells as previ ously reported (Patel, 1973b). These upright cells are too few and too widely spaced to form a sheath around the pro cumbent cells of the heterocellular, multiseriate rays. Although Patel (1973b) did not note spiral thickenings in the imperforate tracheary elements of Ixerba, some of the tracheids examined in this study exhibit fine to coarse spiral thickenings. Many taxonomists have grouped Ixerba with Brexia and Roussea in either the Brexioideae (Engler, 1928; Schulze Menz, 1964; Thorne, 1976) or the equivalent Brexiaceae (Airy Shaw in Willis, 1973; Dahlgren, 1975, 1980, 1983; Takhtajan, 1966). The taxonomic placement of Ixerba is very difficult, however, because the genus shares the wood and leaf anatomical characteristics of the Escallonioideae but has the pollen and ovular characteristics of Brexia. The vegetative anato m y of Ixerba, however, differs in many ways fro m that of Brexia, and argues for the taxono m ic separation of the two genera. Work on floral morphology and anatomy also supports the s e paration of these two genera (Bensel and Palser, 1975a).

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175 Ixerba has no stipules or foliar trichomes, and the vein endings are composed of helically thickened tracheids that are sometimes associated with fibers. Brexia, on the other hand, possesses stipules, foliar trichomes and vein endings that include peculiar sclereids with bulbous exten sions (Ramarnonjiarisoa, 1980). Brexia also has a more com plex petiolar vasculature (Ramamonjiarisoa, 1980) than Ixer ba. Ixerba has large glands composed of cells arranged in regular files in the marginal crenations of the leaves. Brexia, in contrast, lacks glands in the foliar serrations (Ramamonjiarisoa, 1980). The vessel elements of Brexia (Ramamonjiarisoa, 1980) are much shorter than those of Ixer ba and typically have simple perforation plates, whereas, perforation plates in Ixerba are exclusively scalariform. Ixerba wood contains only tracheids but Brexia has both tracheids and fiber-tracheids. Some of the tracheids in Ixerba bear spiral thickenings, whereas, these are absent from all perforate and imperforate elements of Brexia (Rama monjiarisoa, 1980). Finally, Ixerba wood has sparse axial parenchyma that is predominantly apotracheal diffuse or paratracheal scanty. Brexia wood has abundant axial paren chyma that is apotracheal banded (Ramamonjiarisoa, 1980). Despite the differences noted above, both Ixerba and Brexia have bitegmic, crassinucellate ovules, while the Escalloniaceae possess unitegmic, tenuinucellate ovules (Davis, 1966; Philipson, 1974). In addition, Brexia and Ixerba are very similar palynologically and on this basis

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176 could be grouped with Cuttsia, Abrophyllum and Argophyllum in the Escalloniaceae (Hideux and Ferguson, 1976). In recent anatomical work on Brexia and Roussea Rama monjiarosoa (1980) argued that although Brexia and Roussea are saxifragaceous, they are unrelated to the Escallonioid eae and deserve independent status. Roussea is also palyno logically isolated from Brexia and Ixerba and more closely allied to Ribes than to any other saxifragaceous genus ( Hideux and Ferguson, 19 76). Because of the numerous vegetative anatomical and mor phological differences noted previously, Brexia and Ixerba probably are not closely related, and, therefore, Ixerba should be removed from the Brexioideae. The present study indicates that Ixerba is more closely related to Anopterus (Escallonioideae) than to any other saxifragaceous genus. Recent classification systems had advocated such a placement for Ixerba (Takhtajan, 1980, 1983; Thorne, 1983), and Patel (1973b) also included this genus in the Escalloniaceae based upon his study of the wood anatomy of New Zealand Escalloni aceae. Using floral morphology and anatomy, Bensel and Palser (1975a) also tentatively placed Ixerba in the Escal lonioideae. Relationships of Anopterus Anopterus is another genus which has most of the ana tomical features of an archetypical woody saxifrage (Table 3), and it shares many vegetative anatomical features with Ixerba. Both Anopterus and Ixerba have long vessel elements

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177 with scalariform perforation plat es t ha t a re n o t bordered, although Ixerba has more bars p e r scalarif o rm perforation plate than Anopterus. Compared to the rare, irregular uni seriate files of intervascular pits in Ixerba, the irregular intervascular pits of Anopterus are more numerous and are arranged in transitional, opposite or alternate patterns. Both genera possess medium length tracheids with coarse or fine spiral thickenings, although these thickenings are more obvious and numerous in Anopterus than in Ixerba. Anopterus glandulosus, which occurs in subalpine areas of Tasmania (Bentham, 1864), has shorter and narrower vessel elements and shorter tracheids than~ rnacleayanus which occurs in the subtropical regions of eastern and southeastern Queens land and northeastern New South Wales. The variation in length and diameter of the tracheary elements of the two species of Anopterus is probably attributable to adaptations to the different climatic conditions inherent in their lati tudinal separation. This variation in length and diameter of the tracheary elements of Anopterus is consistent with trends noted in other studies of genera with species that grow in widely separated latitudes (Baas, 1973; Graaff and Baas, 1974; Oever, Baas, and Zandee, 1981). The tracheid walls of both Ixerba and Anopterus are approximately the same thickness. The axial parenchyrna in Ixerba and Anopterus is predom inantly apotracheal diffuse, although paratracheal scanty parenchyma also occurs. Ray parenchyma is generally similar in Ixerba and Anopterus with regard to the types of rays

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178 present (homocellular, unis e riate a n d heterocellular, bito multiseriate rays) and the relatively short height and nar row width of these rays (Figs. 25 and 56). Both Anopterus and Ixerba lack foliar trichomes but have prominent glands of similar structure in the marginal crenations of their leaves (Figs. 21, 22 and 52, 53). The leaves of both genera have a thick cuticle and round guard cell pairs in surface view. In addition, the guard cells in transection are oval with small cuticular horns that repre sent the outer ledge overarching a stoma (Figs 20 and 51). The two genera differ somewhat in that Ixerba has a bito triseriate palisade layer, while Anopterus has a unito biseriate palisade layer. Also Ixerba has abundant crystal loids which are probably non-oxalate, whereas, Anopterus has druses which are probably oxalate in the spongy mesophyll. Palynologically Anopterus belongs in the Escallonia ceae, and can be grouped with Escallonia, Forgesia and Valdivia (Hideux and Ferguson, 1976). But Anopterus pollen is intermediate between the above group of genera and the Ixerba, Brexia, Cuttsia, Abrophyllum and Argophyllum group (Hideux and Ferguson, 1976). Seed anatomy also supports inclusion of Anopterus in the Escalloniaceae but shows Ixerba to be an isolated genus (Krach, 1976). The similari ties between Ixerba and Anopterus discussed above may indi cate their close relationship and support their inclusion in the Escallonioideae (or the equivalent Escalloniaceae), as Takhtajan (1980, 1983) and Thorne (1983) have done.

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179 Relationships of Cuttsia and Abrophyllum Two other escallonioid genera, Cuttsia and Abrophyllum, possess all eleven characteristics of a hypothetical arche typical woody saxifrage (Table 3). The close relationship between Cuttsia and Abrophyllum advocated by Engler (1928) in his tribe Cuttsiae of the Escallonioideae is supported by the present study as well as by pollen morphology (Hideux and Ferguson, 1976) and seed anatomy (Krach, 1976, 1977). Both Cuttsia and Abrophyllum possess homocellular, uniseriate rays of upright cells. Both genera also exhibit tall and relatively wide heterocellular rays with perforated ray cells, sheath cells and long tails (Figs, 68, 69 and 78). In addition they both have diffuse or diffuse-in aggregates axial xylem parenchyma with short tangential bands of parenchyma cells that link adjacent vascular rays (Figs. 66 and 76). The wood of both genera is fine-textured and lacks growth rings. Both Cuttsia and Abrophyllum have angular pores, although those of Cuttsia often have rounded corners. The vessel elements of both genera are long and have elongate scalariform perforation plates with perfora tions bordered only at the ends (Figs. 67 and 77). Vessel elements of Cuttsia are narrower and have fewer bars per scalariform perforation plate than the those of Abrophyllum. The tracheids of both genera are very long and have thick walls. Although the tracheids of both genera possess spiral thickenings, these wall ornamentations are fine in Cuttsia and coarse in Abrophyllum.

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180 Cuttsia and AbrophylluIT. l eaves have similar m arginal serrations with hydathode s in each tooth. A flared vein terminates in each serration, and often the tooth apex is composed of thick-walled, darkly staining cells. Ramamon jiarisoa (1980) compared the tooth types among the Escallon ioideae and also noted the similarity of structure between the leaf teeth of Abrophyllum and Cuttsia. Both genera possess elongate, tapered, thick-walled, bulbous-based fo liar trichomes. In Cuttsia and Abrophyllum the midvein and smaller vascular bundles of the leaves have a similar shape and size and are associated with a well-developed bundle sheath and bundle sheath extensions. Especially noteworthy is the constricted adaxial bundle sheath extension from the midvein in both genera (Figs. 63 and 74). Crystal sand occurs in the spongy mesophyll cells, and cleared leaves of certain specimens of both genera exhibit small clusters of yellowish cells in the mesophyll (Figs. 59 and 71). Although Solereder (1908) and Metcalfe and Chalk (1950) stated that the leaves of Abrophyllum bore small glandular hairs, glandular trichomes do not occur on the leaves of Abrophyllum examined. Neither Holle (1893) nor Thouvenin (1890) noted glandular trichomes in this genus. Cuttsia and Abrophyllum display a trilacunar, three-trace nodal configuration which conflicts with a previous report of a unilacunar, one-trace nodal pattern for Abrophyllum ornans (Swamy, 1954). These two genera also show similar seed morphology (Krach, 1976, 1977) and pollen structure (Hideux and Ferguson, 1976).

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181 Cuttsia and Abrophyllum belong in the Escallonioideae and appear to be closely related to one another based upon the numerous similarities in their v egetative anatomy. Relationships of Carpodetus Carpodetus, another genus in the Escallonioideae, shares man y vegetative anato m ical characteristics with both Cuttsia and Abrophyllum. Like the latter two genera, Carpo detus displays the anatomical characteristics of an arche typical wood y saxifrage (Table 3). Engler (1928) placed Carpodetus in the tribe Argophylleae of the Escallonioideae with Argophyllum, Corokia, Colmeiroa and Berenice. Of the three species of Carpodetus studied, arboreus was originally described as a separate genus, Argyrocalymma. The limited material exarr.ined in this study shows that C. arboreus is virtually identical to~ major, and both of these species, from New Guinea, are similar to~ serratus, from New Zealand, in almost all qualitative wood anatomical characteristics. The wood anatomy of the three species of Carpodetus examined supports the inclusion of the genus Argyrocalymma within the genus Carpodetus, as recommended by Schlechter (1914). The only differences among the three species are the abundance, length and diameter of the vessel elements and the length and wall thickness of the tracheids. Carpodetus arboreus and~ ~ajor have fewer pores, longer and wider vessel elements and longer and thicker-walled tracheids than C. serratus. These quantitati v e differences between C. arboreus and C. major, the two tro p ical species,

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182 and f:__ serratus, the temperate species, probably reflect adaptations to widely differing climates rather than any taxonomic distinction between Argyrocalymma and Carpodetus. This pattern of variaton of larger cell dimensions with decreasing latitude is consistent with other wood anatomical studies on genera with representatives in tropical and tem perate latitudes as noted above for Anopterus (Graaff and Baas, 1974; Oever, Baas, and Zandee, 1981). The wood of Carpodetus is similar to that of Cuttsia and Abrophyllum in possessing solitary, angular pores with moderately small diameters. The vessel elements are long with elongate scalariform perforation plates and numerous bars per plate (Fig. 89), as in Cuttsia and Abrophyllum. Carpodetus, however, is distinguished from the latter two genera in that all three species examined have perforations with complete borders, and one species has some vessel elements with fine spiral thickenings. The tracheids of Carpodetus have thick walls with spiral thickenings and are very long, as in Cuttsia and Abrophyllum. Axial xylem parenchyma in all three genera is predominantly diffuse or diffuse-in-aggregates with tangential bands of two to three cells that connect adjacent vascular rays (Fig. 88). The ray tissue is also similar to that of Cuttsia and Abrophyl lum with homocellular, uniseriate rays of upright cells and relatively wide, heterocellular multiseriate rays (Fig. 90). Patel (1973b) also noted the similarities in the ray tissue among these three genera. The heterocellular rays of Carpodetus also have sheath cells and perforated ray cells

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183 with scalariform perforation plates (Figs. 87 and 90), as in the other two genera. While Carpodetus ray cells often contain prismatic crystals (Fig. 89), these inclusions are lacking from the ray cells of Cuttsia and Abrophyllum. A large vein flares as it enters each marginal serra tion in the leaves of C. serratus as previously noted for Cuttsia and Abrophyllum (Figs. 86 and 65). Each tooth apex inf:_ serratus is composed of a number of darkly staining, thick-walled cells as in Cuttsia and Abrophyllum. In addi tion, the midvein and smaller vascular bundles of the leaves of Carpodetus are very similar in shape, size and structure to those of Cuttsia and Abrophyllum (cf., Figs. 61, 63; 73, 74; 84, 85). The vascular bundles of all three genera are surrounded by a well developed bundle sheath, and the mid vein in each also possesses a constricted adaxial bundle sheath extension (Figs. 63, 74 and 85). Although Abrophyl lum has a uniseriate epidermis, Carpodetus and Cuttsia have an adaxial epidermis that is wholly or partially biseriate (Figs. 61, 83 and 84). The mesophyll differs in that Cutts ia and Abrophyllum have a lacunose spongy mesophyll with crystal sand in some cells, while Carpodetus has a compact spongy mesophyll with druses in some cells. The stomatal apparatus is anomocytic in all three gen era, although Philipson (1967) reported that Carpodetus has a paracytic stomata} apparatus. The guard-cell pairs are elliptic in surface view in all three genera. Carpodetus has round seeds that are somewhat similar to those of Cuttsia and Abrophyllum (Krach, 1976, 1977).

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184 Carpodetus has c e rtain features that differ from those in Cuttsia or Abrophyllum, such as the spiral thickenings in some of the vessel elements and the prismatic crystals in the ray parenchyma cells. Another distinguishing feature in Carpodetus is the presence of domatia on the abaxial surface of the leaves (Figs. 80 and 85), which had been noted pre viously (Sampson and McLean, 1965). Carpodetus also ex h ib its variation in the number of cell layers in the adaxial epidermis of its leaves (Figs. 83 and 84). Although Brook (1951) called the innermost layer of the biseriate epidermis of Carpodetus a hypodermis, he did not provide developmental evidence for this description. Thus the exact nature of this epidermal feature is uncertain due to the lack of developmental study. Nevertheless, Brook (1951) noted that the presence of a hypodermis is related to the type of leaf sectioned. Carpodetus has both juvenile and adult leaf forms, and a hypodermis typically is present in the adult leaves but is absent from the juvenile leaves. Thus, the stage of development of a leaf, may account for the varia tion in the extent of the biseriate adaxial epidermis ob served in the present work. Because most of the specimens in this study were not designated as adult and juvenile leaf forms by the collectors, juvenile and adult leaves could not be distinguished. In one specimen of C. serratus (Tomlinson 2-I-69), which had adult and juvenile leaves clearly desig nated, the adaxial epidermis was partly biseriate in both types of leaves. This reported difference (Brook, 1951) in

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185 the number of cell layers in the adaxial epidermis of the two types of leaves requires more intensive study with more material than was currently available. Another difference among Carpodetus, Cuttsia and Abrophyllum is that Carpodetus sheds its pollen in tetrads while the other two genera shed their pollen grains individually (Hideux and Ferguson, 1976). Relationships of Corokia and Argophyllum Besides Carpodetus, the other genera in the tribe Argophylleae of the subfamily Escallonioideae are Corokia, Argophyllum, Colmeiroa and Berenice (Engler, 1928). Berenice now has been placed in the Campanulaceae because of its distinctive pollen morphology and leaf and stem anatomy (Erdtman and Metcalfe, 1963). Corokia carpodetoides was originally the basis of the monotypic genus Colmeiroa, but was combined with the genus Corokia based upon its floral and vegetative morphology (Smith, 1958). The trilacunar, three-trace nodal pattern and the petiolar vasculature of~ carpodetoides are essen tially identical to those of~ macrocarpa (Fig. 94). The semicraspedodromous to brochidodromous leaf venation of these two species is also similar (Figs. 91 and 92). The leaves and twigs of~ carpodetoides were dried rather than fluid preserved, so detailed comparisons of the anatomy of the leaves with that in the other two species of Corokia is difficult. Nevertheless, the shape, size and structure of the midvein and smaller vascular bundles is similar to that

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186 in the other species of Corokia examin e d. Th e adaxial epidermal cells ar e much larg e r than the aba x i a l e p idermal cells in all three species (Figs. 96, 97 and 98). Although they are not as abundant as in the other two species exam ined, multicellular, T-shaped trichomes are common on the abaxial surface of the lea v es of~ carpodetoides (Figs. 96, 97 and 98). One difference in the surface view of the leaves among these three species is the round guard-cell pairs of~ macrocarpa and~ virgata compared to the ellip tic guard-cell pairs of~ carpodetoides. The present mate rials and observations indicate that~ carpodetoides should not be segregated as the monotypic genus Colmeiroa, but rather should be included in Corokia, in concert with the views of Smith (1958). Corokia and Argophyllum show most of the characteris tics of an archetypical woody saxifrage (Table 3), and are very closely related according to their vegetative anatomy. Although tracheids are present in two of the three species of Corokia examined, they are lacking in the species of Argophyllum studied. Nevertheless both genera possess abun dant septate fibers and / or septate fiber-tracheids. The imperforate elements of both genera have medium length and walls of approximately the same thickness. Most of the tracheids and septate fiber-tracheids of Corokia ha v e spiral thickenings while the septate fiber-tracheids and septate fibers of Argophyllum lack these thickenings. Although septate imperforat e elements are absent fro m all other gen era examined in this study, septate fiber-tracheids are

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187 present in at least four other wood y saxifragaceous genera: Choristylis, Hydrangea, Ribes and Deutzia (Ramamonjiarisoa, 1980; Stern, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979b). Both Corokia and Argophyllum have predominantly soli tary pores, although some radial multiples occur in both genera. Radial multiples of pores, however, are more typi cal of Argophyllum than of Corokia (Figs. 107 and 118). The vessel elements of both genera have extremely to very small diameter and medium to long length. These tracheary ele ments bear exclusively scalariform perforation plates with relatively few bars per plate (Figs. 108 and 119). Perfora tions are typically nonbordered. Fine spiral thickenings are present in the vessel elements of both genera. The oval to elongate, minute-diameter intervascular pits of Corokia and Argophyllum are typically alternate (Figs. 108 and 119). Axial parenchyma was not observed in the woods of Corokia or Argophyllum, although Patel (1973a) noted very little scanty paratracheal and diffuse apotracheal paren chyma in three species of Corokia. All other escallonioid genera in this study contain axial parenchyma. The scarcity or lack of axial parenchyma in Corokia and Argophyllum may possibly be related to the abundance of septate fibers and/or fiber-tracheids in their woods. Harrar (1946) ob served that septate fiber-tracheids probably function in place of axial parenchyma, especially where the fibers retain living protoplasts at maturity. Carlquist (1975)

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188 also has noted th a t living or s ept ate fibers substitute for axial parenchyma and commonly occur in woods which lack axial parenchyma. Choristylis, Hydrangea, Ribes, and Deutzia, four woody saxifragaceous genera, also possess septate fiber-tracheids, but generally lack axial parenchyma {Ramamonjiarisoa, 1980; Stern, 1978a; Stern, Sweitzer and Phipps, 1970; Styer and Stern, 1979b). Ray tissue of Corokia and Argophyllum comprises homo cellular, uniseriate rays of upright cells and heterocellu lar, bito multiseriate rays {Figs. 109 and 120). The multiseriate rays of both genera are much shorter and nar rower than the multiseriate rays of Cuttsia, Abrophyllum and Carpodetus but are similar in size to those of Ixerba and Anopterus. Corokia, Ixerba and Anopterus also possess dark staining deposits in the ray parenchyma cells, although these deposits are much more common in Corokia than in the other two genera. The nodal pattern in Corokia and Argophyllum, is typi cally trilacunar, three-trace, although variations occur in both genera. Corokia virgata is enigmatic with a unilacu nar, one-trace nodal pattern (Fig. 95). The two species of Argophyllum examined are trilacunar, three-trace {Fig. 112), while a pentalacunar, five-trace nodal pattern has been reported for A. laxum {Swamy, 1954). The leaves of Argophyllu m typically possess small den tations along the margin whereas the leaves of Corokia are usually entire. Corokia collenettei, however, may have a few marginal dentations {Smith, 1958). The leaves of

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189 Corokia and Argophyllum exhibit a weakly differentiated, typically biseriate palisade layer, although this layer is less distinct in Argophyllum than in Corokia (Figs. 96, 97 and 113). In both genera the cells in one or both layers of the palisade tissue typically contain dark-staining deposits (Figs. 9 7 and 113). The two species of Argophyllum examined in this study belong to the section Brachycalyx. Plants within this section of the genus have either a hypodermis or a palisade mesophyll composed of square or rectangular cells rather than columnar cells in transection (Holle, 1893; Zemann, 1907). This type of palisade was not found in any other genus studied and is not typical of any other woody saxifragaceous genus. Leaves of Corokia and Argophyllum bear unique T-shaped trichomes on the abaxial surface. The terminal cell of these trichomes is lignified and is separated from the uppermost stalk cell by a perforated or pitted septum (Figs. 102, 105, 115 and 116). Other workers also have noted the distinctive multicellular, T-shaped trichomes on leaves and flowers of Corokia (Eyde, 1966; Solereder, 1908; Sertor ius, 1893; Weiss, 1890), and the similar trichomes in Argophyllum (Eyde, 1966; Holle, 1893; Zemann, 1907). In both genera the stomatal apparatus is anomocytic, and the stomata are raised above the level of the abaxial epidermis by enlarged or curved epidermal cells (Figs. 101 and 115). But the two genera differ because Corokia displays

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190 ornamentations on the outer periclinal walls of abaxial epidermal cells below the midvein (Fig. 99), while Argo phyllum lacks this feature. The numerous anatomical similarities outlined above for Corokia and Argophyllum support their close taxonomic posi tion. Corokia and Argophyllum also show resemblances in floral morphology and anatomy (Eyde, 1966) and in pollen morphology (Ferguson and Hideux, 1978). Palynologically these two genera are very closely related and may be linked with the tribe Cuttsiae of the Escallonioideae on the one hand and the Cornaceae on the other (Hideux and Ferguson, 1976). Despite these vegetative and floral anatomical, and palynological similarites, these two genera are very dis tinct from one another based upon seed anatomy (Krach, 1976). The familial affinity of these two genera is still unclear. Most taxonomists have typically placed Argophyllum in the saxifragaceous Escallonioideae (or the equivalent Escalloniaceae), while they have placed Corokia in either the Escallonioideae or the Cornaceae (Dahlgren, 1980, 1983; Takhtajan, 1980, 1983; Thorne, 1983). Relationships Among the Escallonioideae Vegetative anatomical data do not support the mainte nance of the tribe Argophylleae of the Escallonioideae as envisioned by Engler (1928). Engler's Argophylleae contains the genera Argophyllum, Corokia and Carpodetus, discussed in detail above, as well as Berenice (to Campanulaceae, Erdtman

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191 and Metcalfe, 1963) and Colmeiroa (=Corokia, Smith, 1958). Carpodetus, for example, shares more anatomical features with Cuttsia and Abrophyllum (tribe Cuttsieae) than with Argophyllum and Corokia. The latter two genera have shorter vessel elements with fewer bars per scalariform perforation plate and shorter imperforate elements than Cuttsia, Abro phyllum or Carpodetus. In addition, Corokia and Argophyllum have septate imperforate elements which are lacking in the other escallonioid genera. The radial multiples of pores in the wood of Argophyllum and Corokia are also unique features in the Escallonioideae. Likewise no other escallonioid genus has multicellular, T-shaped foliar trichomes or dark staining deposits in the mesophyll cells such as occur in Corokia and Argophyllum. The entire leaf margin in Corokia is not the common condition among the Escallonioideae either. Hydathodes or glands are abundant in the other escallonioid genera studied, but are not common in either Corokia or Argophyllum. Despite the vegetative anatomical differences between Argophyllum and Corokia, and the Escallonioideae (=Escallon iaceae), Hideux and Ferguson (1978) use palynological simi larities to place Argophyllum in the Escalloniaceae in close proximity to Cuttsia, Abrophyllum, Ixerba and Brexia. In contrast, Hideux and Ferguson note that Corokia is inter mediate between the Escalloniaceae and the Cornaceae. Krach (1976) also places Argophyllum in the Escalloniaceae because of its round seeds which are similar to those of Cuttsia and Abrophyllum.

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192 Corokia and Argophyllum possibly should be removed from the Escallonioideae and placed among the Hydrangeoideae of the Saxifragaceae. Two hydrangeoid genera, Hydrangea and Deutzia, also possess complex, multiseriate, foliar tri chomes and septate imperforate elements (Stern, 1978a; Styer and Stern, 1979b). As noted above, the ornamentations on the outer periclinal walls of the abaxial epidermal cells below the midvein of Corokia (Fig. 99) also occur in Phila delphus (Styer, 1978), another hydrangeoid genus. Much more work is needed, however, to confirm a relationship between Corokia and Argophyllum, and the Hydrangeoideae. Some taxonomists place Corokia in the Cornaceae (Cron quist, 1981; Dahlgren, 1980, 1983). Previous workers have noted a similarity between the woods of Cornus and Corokia (Adams, 1949; Li and Chao, 1954), but these woods also have various differences. Although some species of Cornus may have septate fiber-tracheids (Li and Chao, 1954), Corokia wood has an abundance of these specialized imperforate ele ments. In addition, Cornus wood rays are heterocellular, uni-, biand multiseriate while wood rays of Corokia are homocellular, uniseriate with upright cells and heterocellu lar, bito multiseriate. Corokia wood also may have per forated ray cells, whereas these cells are lacking in Cornus (Adams, 1949; Li and Chao, 1954). Among the earlier wood anatomical studies of the Cornaceae (Adams, 1949; Li and Chao, 1954; Patel, 1973a), only Patel noted septate fibers in the wood of Corokia. Floral anatomy and morphology led

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193 Eyde (1966) to reject an y ta xo non , ic affinit y between Cornus and Corokia. Serological data also indicate that Corokia is distinct from the Cornacea e and is more closel y allied to the Saxifragaceae (Fairbrothers, 1977 and pers. comm.; Fairbrothers et al., 1975). According to Ferguson and Hideux (19 7 8) Corokia pollen indicates a possible link between the Cornaceae and the Escalloniaceae, however, vegetative anato m y (Patel, 1973b), floral anatomy {Eyde, 1966) and phytochemistry (Fairbroth ers, 1977; Fairbrothers, et al., 1975) contradict this connection. Corokia and Argophyllum are certainly closely related, but their position in the classification of the dicotyledons remains unclear. Cronquist {1981), interest ingly, has recently designated Corokia as a nonmissing link between the Cornaceae and the Grossulariaceae (incl. Escal loniaceae). Detailed, systematic anatomical work on the Cornaceae is needed to determine the proper taxonomic place ment of Corokia and Argophyllum and the relationship of the Saxifragaceae to the Cornaceae. Possible Delimitation of the Escallonioideae The six genera in the Escallonioideae examined in this study (i.e., Anopterus, Cuttsia, Abrophyllum, Carpodetus, Corokia and Argophyllum) possess most of the features of a hypothetical archetypical woody saxifrage {Table 3). Ixerba also can be added to these six genera because of its anatom ical similarities to Anopterus. Besides the morphological and anatomical resemblances mentioned previously, these

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194 s even ge ne r a als o posses s s imp l e , p r e d om ina n tl y alternate, p e tiolat e , exstip u l a te lea v es with s e rrate or crenate mar gins. Additionally th e y hav e a trilacunar, three-trace nodal pattern. T h is combination of nodal and leaf charac teristics is not commonly found among the angiosperms (Sinnott and Bail ey , 1914; Bailey, 1956). Sinnott and Bailey, and Bailey found that taxa with trilacunar nodes and dentate or s e rrate leaves generally possess stipules, while those with unilacunar nodes and entire leaves generally lack stipules. This distincti v e set of nodal and leaf characteristics is present in all of these escallonioids except Corokia, which has mostly entire leaves and both unilacunar and trilacunar nodal configurations, and Argophyllum, which may have either a trilacunar, three-trace or a pentalacunar, five-trace nodal pattern (Swamy, 1954). Thus alternate, exstipulate, serrate or crenate leaves and a trilacunar, three-trace nodal pattern may delimit the Escallonioideae (Escalloniaceae) from other woody saxifrages. Based upon recent anatomical work, Ramamonjiarisoa (1980) has also placed Forgesia and Choristylis in the Escallonioideae. While Forgesia is similar anatomically to the escallonioid genera examined in this study, Choristylis is quite distinct. The only characteristic which links Choristylis with the Escallonioideae is the structure and morphology of the marginal teeth. Choristylis has rounded pores, septate fibers, relatively few bars per scalariform perforation plate, and relatively short vessel elements (Ramamonjiarisoa, 1980). These characteristics in

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r I 195 Choristylis are inconsistent with a position in the Escal lonioideae. The presence of minute stipules in Choristylis (Watari, 1939; Ramamonjiarisoa, 1980), and the palynologi cal similarity between this genus and Itea (Hideux and Ferguson, 1976) seems to exclude Choristylis from the Escal lonioideae. Relationships of Tetracarpaea Another genus whose taxonomic affinities are uncertain is Tetracarpaea. Some taxonomists consider this genus to be a monotypic family, the Tetracarpaeaceae (Airy Shaw in Willis, 1973; Dahlgren, 1980, 1983). Other workers place Tetracarpaea in the Escalloniaceae (Hutchinson, 1967; Takhtajan, 1980, 1983), Grossulariaceae (Cronquist, 1981) or Cunoniaceae (Bentham, 1864). Tetracarpaea possesses most of the characteristics of an archetypical woody saxifrage, but lacks the unicellular foliar trichomes, hydathodes or glands in the marginal ser rations and a trilacunar, three-trace nodal pattern (Table 3). Qualitatively the wood of Tetracarpaea is very similar to that of the escallonioid genera Ixerba, Anopterus, Cutts ia, Abrophyllum and Carpodetus. Tetracarpaea wood, however, has cells with much smaller dimensions than those of the Escallonioideae. The vessel elements of Tetracarpaea have extremely small diameters, short to medium lengths and very few bars per scalariform perforation plate (Figs. 8 and 9). Tetracarpaea also has extremely short tracheids. The ray cells of Tetracarpaea also contain abundant dark-staining

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196 deposits (Figs. 9, 11 and 12) which are typically absent from the ray cells of the Escallonioideae. Although the wood is typically saxifragaceous, the nodes and leaves of Tetracarpaea are atypical for a woody saxifrage. Tetracarpaea possesses a unilacunar, one-trace nodal pattern, which confirms a previous report for the genus (Swamy, 1954). The leaves of Tetracarpaea possess simple craspedodromous venation and areole development is typically lacking or incomplete (Fig. 1). Other members of the Escallonioideae have semicraspedodromous venation, and areole development is incomplete to imperfect. Veinlets are straight and tapered in Tetracarpaea (Fig. 2), while they are straight, curved or branched and variously shaped in the escallonioid genera. The marginal serrations of Tetracarpaea have the appearance of hydathodes, but water pores are not visible in the adaxial epidermis. The genera of the Escallonioideae, however, typically possesses glands or hydathodes in their marginal serrations or crenations. In Tetracarpaea the outer ledge overarching a stoma is represented by two large cuticular horns (Fig. 5) while this ledge is represented by very small cuticular horns in Ixerba, Anopterus, Cuttsia, Abrophyllum and Carpodetus (Figs. 20, 51, 75). Abaxial fibers are typically associated with the foliar vascular bundles of Tetracarpaea, but they are not a common feature of the Escallonioideae. These cells, however, may be present in Ixerba and Anopterus. Bundle sheaths do not occur in Tetracarpaea but are

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197 characteristic of all other wood y saxifrages examined in this study and previous studies (e.g., Stern, 1974a, 1978a; Styer and Stern, 1979a, 1979b). Despite the similarities in wood anatomy, the numerous differences in leaf anatomy between Tetracarpaea and the Escallonioideae (=Escalloniaceae) argue for the exclusion of this genus from the subfamily (family). The unilacunar nodal pattern, lack of bundle sheaths, craspedodromous vena tion, straight veinlets and lack of hydathodes or glands support the separation of Tetracarpaea from the Escalloni oideae. The distinctive apocarpous gynoecium and tetramer ous flowers (Dickison, pers. comm.) also support this conclusion. . Pollen morphology supports a position for Tetracarpaea in the Cunoniaceae (Hideux and Ferguson, 1976). Although recent studies of the wood anatomy of the Cunoniaceae (Dickison, 1980a) indicate that this may be a valid place ment, the nodal structure, leaf anatomy and floral morphol ogy and anatomy of Tetracarpaea are inconsistent with those of the Cunoniaceae (Dickison, 1975, 1980b and pers. comm.). Seed morphology and anatomy also support the view that Tetracarpaea is very isolated within the woody saxifrages and could easily be considered in its own family (Krach, 1976). Because of the unilacunar, one-trace nodal pattern, the distinctivness of its leaf structure, floral morphology, and seed morphology and anatomy, Tetracarpaea is isolated among the Saxifragaceae and may belong in its own family, the

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198 Tetracarpaeaceae. The similarities in wood anatom y and palynology among the Tetracarpaeaceae, the Cunoniaceae and the Saxifragaceae lend support to a close relationship among these three families in the order Saxifragales. Relationships of Bauera Bauera, like Tetracarpaea, possesses most of the quali tative wood anatomical characteristics of an archetypical woody saxifrage, but nodal and leaf anatomy differ from that in most of the woody saxifrages for which anatomical data exist (Table 3). Bauera wood is similar to that of most woody saxifrages with scalariform, transitional to opposite intervascular pitting, sparse axial parenchyma, and the presence of tracheids (Table 3). Although the wood of Bauera possesses mostly solitary pores, radial multiples and clusters are common (Fig. 39). Most woody saxifrages, how ever, have very few, if any, radial multiples or clusters of pores. The vessel elements with predominantly simple per foration plates and transverse to oblique end walls (Fig. 40) also separate Bauera from other woody Saxifragaceae which display scalariform perforation plates and oblique vessel element end walls. The vessel elements and tracheids are much shorter in Bauera than in any of the Escallonioideae. Spiral thickenings, a characteristic feature of the woody saxifrages, are rarely present in the vessel elements of Bauera. This genus is similar to the Escallonioideae with its homocellular, uniseriate rays of upright cells and

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19 9 heterocellular, multiseriate rays. Bauera also has per forated ray cells, as in the Escallonioideae, although the perforations are simple rather than scalariform (Fig. 41). The rays of Bauera can be distinguished from those of other woody saxifrages because of the dark-staining deposits and the fenestriform pitting between the ray parenchyma and vessels. Bauera is unique among the genera in this study because of the groups of three foliaceous appendages that occur at a given node. Most workers interpret these three structures as three leaflets of a sessile, trifoliolate leaf rather than a simple leaf accompanied by two lateral, foliaceous stipules (Bentham, 1864; Cronquist, 1981; Thouvenin, 1890; Watari, 1939; Willis, 1972). Baillon (1872), however, described Bauera with opposite simple leaves, with each leaf accompanied by two lateral foliaceous stipules. Thouvenin (1890) rejected this interpretation based upon his anatomi cal studies, and argued that the single leaf trace trifur cates in the extreme base of a leaf. He noted that in this part of a leaf the tissues of the leaf and stem intermingle and are not easily distinguishable from one another. Thouvenin's interpretation is inappropriate for several reasons. First, each of the three foliaceous appendages has a small stalk and is vascularized by a single trace. If these appendages represent three leaflets of a trifoliolate leaf, then these stalks are petiolules. However, these "petiolules" are not attached to a petiole, but are attached

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200 directly to th e ste m . Th e latt e r condition is rare among plants that b e ar co m pound leave s . S e cond, the single trace from a nod e trifurcat e s at approximately the same level in the stem as the separation of the two branch traces from the stem vasculature. This vascular pattern supports the con tention that this trifurcation occurs in the stem of Bauera, and not in the e x treme bas e of a sessile, compound leaf. Third, periderm is formed at the expanded portion of a stem where the three foliaceous appendages are attached. This location of periderm also supports the interpretation that this cushion is stem material and not the base of a leaf. One drawback to the above interpretation of the three foliaceous appendages in Bauera is that unilacunar nodal configurations are not typically associated with stipules (Sinnott and Bailey, 1914; Bailey, 1956), although this combination of characteristics is found in some groups (e.g., Galium in the Rubiaceae). In fact, two lateral traces branch from a single trace in Galium to vascularize its interpetiolar or lateral stipules (Tyler, 1897). Foli aceous stipules also occur in a number of unrelated families (Lubbock, 1894). The same condition may exist in Bauera. More conclusive evidence about the proper morphological interpretation of these three foliaceous appendages will require developmental studies and the examination of much more material than was presently available. The leaves of Bauera differ from those of the Escal lonioideae in several ways. Vein areole development is typically lacking, although it may be incomplete. In the

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201 other woody saxifrag es vein areole development is usually incomplete to imperfect. The vein endings of Bauera are unique because of the enlarged, short tracheids at the terminus of each vein ending (Fig. 29). The vein endings in the other genera are typically composed of helically thick ened, elongate tracheids. Although the upper epidermis of Bauera leaves may be biseriate, it differs from the biseriate adaxial epidermis in Cuttsia and Carpodetus. In Bauera the cells of the two layers of the biseriate epidermis differ widely in size and shape (Fig. 33), while in Cuttsia and Carpodetus the cells of the biseriate epidermis are relatively similar in size and shape (Figs. 61 and 83). In addition, the ledges over arching a stoma are represented by large cuticular horns in Bauera (Fig. 36), while these ledges are represented by small cuticular horns in Ixerba, Anopterus, Cuttsia, Abro phyllum and Carpodetus. Bundle sheaths are typically pres ent in woody saxifrages, however, bundle sheaths are absent from the leaves of Bauera. Unicellular, thick-walled tri chomes occur in this genus as in other woody saxifrages (Table 3), although the base of these trichomes is surround ed by a ring of en 1 arged epiderma 1 ce 11 s which do not occur in the other saxifragaceous genera (Fig. 33 and 34). Bauera is the only genus is this study which possesses prismatic crystals in its leaves (Fig. 32). Bauera is morphologically and anatomically distinguish able from all other genera in this study as well as from

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202 other wood y sa x ifrages. Opposite lea v es with foliaceous stipules do not occur in the Saxifragaceae. In addition, simple perforation plates in the vessel elements and unila cunar, one-trace nodes are not typical for members of the Saxifragaceae. Palynologically Bauera also is isolated from other Saxifragaceae and may be classified in its own sub family or family (Wakabayashi, 1970) or placed among the advanced genera of the Cunoniaceae (Erdtman, 1952; Hideux and Ferguson, 1976). Work on embryology also supports the inclusion of Bauera in the Cunoniaceae (Prakash and McAlis ter, 1977). Current observations indicate that Bauera has some affinity to both the Saxifragaceae and the Cunoniaceae but in many ways is isolated from both families. Because of the numerous vegetative anatomical and morphological differ ences between Bauera and the other genera in this study it appears to be unrelated to them or to any other woody saxi frage. Bauera, like Tetracarpaea, possibly should be placed in its own family. Relationships of Anodopetalum Anodopetalum does not fit the anatomical pattern of an archetypical woody saxifrage and belongs in the Cunoniaceae, as suggested previously (Dickison, 1980a). Its opposite leaves with interpetiolar stipules and the trilacunar, three-trace nodal pattern with split lateral traces (Dicki son, 1980b) have not been found among the woody Saxifraga ceae. Its complex petiolar vasculature which results in a dorsally flattened concentric vascular bundle or ring of

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203 bundles is also characteristic of the Cunoniaceae (Cronquist, 1981; Dickison, 1975) and atypical for the woody saxifrages. Although a concentric ring of vascular bundles does occur in the petioles of some woody saxifrages, such as Abrophyllum and Anopterus, these taxa have alternate leaves, lack stipules and possess trilacunar, three-trace nodes without split lateral traces. The epidermal leaf cells of Anodopetalum have straight anticlinal walls, as do most of the Cunoniaceae, while most of the woody saxifrages possess epidermal leaf cells with curved or sinuous anti clinal walls. Interestingly, Anodopetalum possesses glands in the marginal crenations of its leaves that are very similar to those found in the leaves of Ixerba and Anopterus. In all three genera the gland is relatively large and composed of radial files of cells that have dark-staining contents. In addition, the crenations in all three genera are vascular ized by an arc of vascular tissue rather than a single vein (Figs. 21, 52 and 138). These genera also display guard cell pairs with a circular rather than an elliptic outline in surface view. These few similarities in the leaves of these three genera are insufficient to support the inclusion of Anodopetalum in the Saxifragaceae, but may support a close connection between the Cunoniaceae and Saxifragaceae. The wood of Anodopetalum has clustered pores and vessel elements with predominantly simple perforation plates, whereas the woody saxifrages typically possess solitary pores and v essel elements with scalariform perforation

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204 plates. In addition heterocellular rays and perforated ray cells are largely absent from the wood of Anodopetalum, while these structures commonly occur in most woody saxi frages (Table 3). The length of the tracheids of Anodopet alum is moderately short to medium, while most woody saxi frages typically have medium to moderately long tracheids. The axial parenchyma in Anodopetalum is relatively abundant compared to the sparse axial parenchyma in woody saxifrages. Axial parenchyma is diffuse-in-aggregates and marginal in Anodopetalum, but typically diffuse-in aggregates in woody saxifrages. Axial parenchyma and ray parenchyma cells of Anodopetalum are filled with starch grains and dark-staining deposits, whereas these deposits are typically absent from woody saxifrages. Based upon the numerous anatomical and morphological differences between Anodopetalum and the Saxifragaceae, this genus appears misplaced in the Saxifragaceae and should remain in the Cunoniaceae. Ingle and Dadswell (1956) and Dickison (1980a) also include Anodopetalum in the Cunonia ceae and place it among the more advanced members of the group. Seed anatomy (Dickison, 1984) and pollen morphology (Hideux and Ferguson, 1976) are consistent with this view. Relationships of Aphanopetalum Aphanopetalum is another genus often placed in the Cunoniaceae, although Dickison (1975c, 1980b) has questioned this taxonomic arrangement. Thorne (1983) also was unsure about the familial affinities of this genus and placed it

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205 among his incertae sedis. The Cunoniaceae typically have trilacunar, three-trace nodes and vascularized stipules, whereas Aphanopetalum has unilacunar, one-trace nodes and avascular stipules. Aphanopetalum is different from the Saxifragaceae in many ways. This genus is stipular with opposite leaves, while woody saxifrages are generally estipular with alter nate leaves. Aphanopetalum has unilacunar, one-trace nodes, whereas trilacunar, three-trace nodes predominate in the woody saxifrages. The bundle sheaths of Aphanopetlum also are less well-developed and distinct than those in the woody saxifrages (Figs. 48, 61, 73, 84, 147). Although the biser iate palisade layer and lacunose spongy mesophyll of Aphano petalum typically occur in the woody saxifrages, Aphanopet alum is distinctive because many of its mesophyll cells contain dark-staining deposits, a rare condition in the woody saxifrages (Figs. 97 and 113). Palynologically this genus also is isolated from the Saxifragaceae and the Cunon iaceae (Hideux and Ferguson, 1976). Although Aphanopetalum has both differences and simi larities with the woody Saxifragaceae, the differences out weigh the similarities and argue for the continued exclusion of this genus from the Saxifragaceae. The taxonomic place ment of Aphanopetalum awaits further anatomical and morpho logical study, especially of the wood.

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206 Relationships of Don a tia Another ge n us whose taxonomic position is uncertain is Donatia. Taxonomists have placed this genus in the Saxifragaceae (Engler, 1890; Hooker, 1865) the Stylidiaceae (Dahlgren, 1975, 1980, 1983; Mildbraed, 1908; Mueller, 187 9 ; Thorne, 1976; Wagenitz, 1964) or the Donatiaceae (Airy Shaw in Willis, 1973; Cronquist, 1981; Skottsberg, 1915; Takhtajan, 1980, 1983). Engler (1928) later was uncertain of Donatia 's taxonomic placement (Table 1 ). Donatia is unrelated to the genera examined in this study, nor does it share many anatomical characteristics with other woody saxifrages. The sessile leaves of Donatia contrast with the typically petiolate leaves of most of the Saxifragaceae. The suprabasal, acrodromous venation and lack of areole development in Donatia contrasts with the typically semicraspedodromous venation and imperfect to incomplete areole development of the other saxifragaceous genera in this study. While Philadelphus also has supra basal acrodromous venation, it possesses petiolate dorsiven tral leaves with some areole de v elopment (Styer and Stern, 1979b). Although isobilateral leaves occur in both Donatia and some species of Escallonia (Stern, 1974a), only Donatia possesses an undifferentiated mesophyll. All other saxi frages studied have dorsiventral lea v es with differentiated palisade and spongy mesophyll layers. Donatia also is dis tinctive because of the large masses of lignified, densely staining parenchyma cells abaxial to the small vascular bundles (Fig. 125). This lignified parench y ma previously

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2 07 has been called sclerenchyma (Chandler, 1911; Rapson, 1953). Donatia leaves have stomata in both epidermal lay ers, an uncharacteristic condition in the Saxifragaceae. Multicellular, uniseriate trichomes are unknown from the woody saxifrages, although they do occur in Donatia and in the herbaceous saxifrages (Metcalfe and Chalk, 1950). These trichomes in herbaceous saxifrages, however, lack the oblique, pitted or perforated crosswalls characteristic of Donatia (Fig. 130). The wood of Donatia is distinct from that of the Saxi fragaceae because of its clustered pores, abundant axial parenchyma, fibers with simple pits and lack of spiral thickenings in tracheary elements. The poorly developed secondary xylem is similar to the wood of other Saxifraga ceae, however, because of the vessel elements with scalari forrn perforation plates and scalariform intervascular pitting. The small amount of wood produced by Donatia and the qualitative differences between Donatia wood and that of other Saxifragaceae argue for the exclusion of this genus from the family. The leaf anatomy of Donatia is distinct from that in most of the Saxifragaceae, as noted above. Previous workers have also excluded Donatia from the Saxi fragaceae based upon anatomical data (Chandler, 1911; Rap son, 1953). Despite the numerous differences in vegetative anatomy, the woody Saxifragaceae and Donatia both have uni tegQic tenuinucellate ovules (Philipson, 1974; Philipson

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2 08 and Philipson, 1973). This similarity is insignificant, however, because the saxifrages have no haustorial develop ment during endosperm formation (Davis, 1966), as is charac teristic of Donatia (Philipson and Philipson, 1973). Palynologically, Donatia is more similar to the Campanu laceae than to the Saxifragaceae (Erdtman, 1952). Donatia has been included among the Stylidiaceae pri marily because of its resemblance to Phyllachne, another cushion plant, and the presence of inulin as its food stor age product (Mildbraed, 1907; Mueller, 1879). Mildbraed (1907) placed Donatia within its own subfamily in the Sty lidiaceae. Donatia also has a similar embryology to the stylidiaceous genus Forstera with its unitegmic tenuinucel late ovules and endospermal haustoria, but is distinct from other Stylidiaceae in the development of its ovules (Philip son and Philipson, 1973). The Philipsons have suggested that Donatia should be placed in its own family, and that the Donatiaceae is allied to the Stylidiaceae. Carolin (1960), however, has supported the inclusion of Donatia in the Stylidiaceae, and has argued that the flowers of Donatia formed the basis from which the more specialized sympetalous flowers of other Stylidiaceae were derived. Floral anatomy is uniform in the Stylidiaceae regarding the number of vascular bundles supplied to the floral organs, but Donatia for~s no column or gynostemium, a characteristic of the other stylidiaceous genera (Carolin, 1960). Donatia, how ever, is anatomically different from the Stylidiaceae be cause of its scalariform perforation plates, lignified

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20 9 ground tissue in the stem, "sclerenchyma" adjacent to the main veins and paracytic stomatal pattern (Chandler, 1911; Rapson, 1953). This and other studies have shown that Donatia is apparently an independent lineage and should be placed in its own family, but the closest relatives of the Donatiaceae remain obscure. More work is needed to determine the tax onomic placement of this enigmatic genus. Australasian Genera and Geological History The anatomical similarities and possible taxonomic affinities among selected groups of genera discussed in detail above may lend support to Raven and Axelrod's (1972) ideas about the influence of past continental movements on biogeography in Australasia. Specifically, similarities among certain pairs or groups of genera may support the idea of an ancient connection between Australia, New Zealand, New Caledonia, New Guinea and other South Pacific Islands. Those genera with comparable anatomy and which occur in Australia and New Zealand include: Anopterus and Ixerba; Cuttsia, Abrophyllum and Carpodetus; and Argophyllum and Corokia. The latter two genera also are found in New Cale donia and other South Pacific Islands, respectively, and Carpodetus also occurs in New Guinea. Thus the affinities among these genera provide evidence for the possibility of an ancient connection among these Australasian land masses. This possibility, however, must be tempered by the likeli hood of long distanc e dispersal and subsequent adaptive

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210 radiation of some of these taxa. Long distance dispersal is especially pertinent to the biogeography of Corokia, which has one species on Rapa, a volcanic island. Further conclu sions about geological history, long distance dispersal and biogeography of these plants from the antipodes would re quire more precise analysis of their pollination biology, seed dispersal, distributions and habitats than possible here. These studies remain to be done.

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CONCLUSIO N S Although certain anatomical features are distinctive for each of the twelve Australasian genera in this study, other characteristics are fairly constant throughout these plants. The leaves of the genera studied are typically dorsiventral and possess uniseriate epidermides, although isobilateral leaves and biseriate epidermides also occur in certain genera. Most genera also have an anomocytic stoma tal apparatus. The vein architecture is typically semicras pedodromous, although some genera possess craspedodromous, brochidodromous or acrodromous venation. The nodal pattern is usually trilacunar, three-trace, although unilacunar, one-trace patterns also occur. The wood of these plants is typically diffuse porous with narrow diameter, thin-walled, angular, solitary pores and long vessel elements with oblique end walls and scalari form perforation plates. Scalariform, transitional and opposite intervascular pitting patterns also are common. The imperforate elements are usually tracheids. Both tra cheids and vessel elements typically possess spiral thicken ings. The axial xylem parenchyma in these genera is mostly sparse or absent. The ray parenchyrna is composed of homo cellular uniseriate rays of upright cells and heterocellular, bito multiseriate rays. in most of these genera. 211 Perforated ray cells occur

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212 Of th e t we l ve g e n e ra ex amined in this study, Cuttsia, A b rophyllu m and Carpodetus possess all ele ve n anatomical features of an arch e ty p ical woody saxifrage. Ixerba and Anopterus are similar to these three genera in this respect, exc e pt the y lack foliar trichomes (Table 3). Corokia and Argophyllurn possess most of the ele v en anatomical features, except for multicellular tricho m es and general lack of hyda thodes and / or glands in their leaves (Table 3). The wood of Tetracarpaea and Bauera exhibits most of the characteristics of an archetypical wood y saxifrage, although Bauera has p redominantly simpl e perforation plates. The leaf anatomy of these two genera, however, differs fro m the other woody saxifrages. Both Donatia and Anodopetalurn share few charac teristics of an archetypical woody saxifrage (Table 3). The leaves and nodal anatomy of Aphanopetalum also are distinct fro m the other saxifrages. Ixerba and Anopterus exhibit prominent glands of simi lar structure in the marginal crenations of their leaves, and share many other anatomical features. Both genera have long vessel elements with scalariform perforation plates that are not bordered. They also possess medium length tracheids with coarse or fine spiral thickenings. The ray parenchyma also is generally similar between the two genera. their rays ar e shorter and narrower than those of the other escallonioid genera. These two genera differ in that Ixerba possesses large crystalloids while Anopterus has druses. Although Ixerba previously has been allied with Brexia and Roussea in the Brexioideae, Ixerba and Brexia are not

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213 closely related because of their differences in vegetative anatomy as w e ll as floral morphology and anatomy. Ixerba should be removed from the Brexioideae, as it appears more closely allied to the Escallonioideae, especially Anopterus, than to any other members of the Saxifragaceae. Three other escallonioid genera, Cuttsia, Abrophyllum and Carpodetus, possess all the characteristics of an arche typical woody saxifrage and undoubtedly belong in the Escal lonioideae (Table 3). Cuttsia and Abrophyllum are very similar, and, despite a few anatomical differences, Carpo detus is clearly allied to these genera. Leaf serrations in all three genera exhibit an apical callosity composed of thick-walled, dark-staining cells. Also, a large vein flares as it enters the marginal leaf serrations. Carpo detus, however, is the only genus studied which has domatia on the abaxial leaf surface. The midvein and smaller vascu lar bundles of the leaves of all three genera are similar in size, shape and cellular composition. In addition, the midvein of each genus displays a constricted adaxial bundle sheath extension. Abrophyllum has a uniseriate adaxial epidermis, while Cuttsia and Carpodetus possess a biseriate adaxial epidermis. The wood of Cuttsia, Abrophyllum and Carpodetus is similar in having solitary, angular pores with moderately small diameters. All three genera possess long vessel ele ments with elongate scalariform perforation plates and numerous bars per plate. The tracheids are very long and have thick walls with spiral thickenings. Axial parenchyma

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214 is diffuse or diffuse-in-aggregates with tangential bands of two to three cells that connect adjacent vascular rays. Their ray tissue is similar with homocellular, uniseriate rays of upright cells and relatively wide, heterocellular, multiseriate rays. The heterocellular rays exhibit sheath cells and perforated ray cells with scalariform perforation plates. Carpodetus, though, is distinct from Cuttsia and Abrophyllum because some of its ray cells contain prismatic crystals and its vessel elements have spiral thickenings. The other members of the Escallonioideae examined in this study, Corokia and Argophyllum, are very similar ana tomically and possess most of the characteristics of an archetypical woody saxifrage (Table 3). Both genera, how ever, differ in many ways with these other genera and may not belong in the Escallonioideae. The leaves of Corokia are typically entire while those of Argophyllum possess small marginal dentations. Escallonioid leaves are usually serrate. The palisade layer of both genera is weakly dif ferentiated and these cells may contain dark-staining depos its that are atypical of the other Escallonioideae. Both Corokia and Argophyllum also bear unique, multicellular, shaped, foliar trichomes. Although the stomatal apparatus is anomocytic in all Escallonioideae, the guard cells in Corokia and Argophyllum are unique in that they are raised above the rest of the abaxial surface by enlarged epidermal cells. Guard cells are even with the abaxial epidermis in other escallonioids.

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215 Although Corokia and Argophyllum have predominantly solitary pores in their wood, radial multiples also occur. Among the genera studied only Corokia and Argophyllum pos sess septate imperforate elements. The ray tissue of both Corokia and Argophyllum is composed of homocellular uniser iate and heterocellular bito multiseriate rays as in other escallonioids. The multiseriate rays of both genera, how ever, are much shorter and narrower than the multiseriate rays of Cuttsia, Abrophyllum and Carpodetus but are similar in size to those of Ixerba and Anopterus. Corokia, Ixerba and Anopterus also possess dark-staining deposits in their ray parenchyma cells. These deposits are typically lacking in the other genera. Corokia and Argophyllum are certainly closely related, but their taxonomic position is uncertain. They share cer tain characteristics with both the woody Saxifragaceae and the Cornaceae. Based upon vegetative anatomy, as well as floral morphology and anatomy, Corokia and Argophyllum are readily distinguishable from the Escallonioideae and should possibly be placed elsewhere among the woody Saxifragaceae. Their taxonomic placement awaits further study, especially of the vegetative anatomy of the Cornaceae. The six genera in the Escallonioideae examined in this study (cf., Table 1) possess most of the features of an archetypical woody saxifrge (Table 3). Ixerba also can be included among this group because of its anatomical similar ities with Anopterus. Except for some exceptions in Corokia and Argophyllum, these seven genera typically possess

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216 simple, predominantly alternat e , petiolate, exstipulate leaves with serrate or crenate margins that arise from a trilacunar, three-trace node. This atypical combination of nodal and leaf characteristics may delimit the Escalloni oideae from all other woody Saxifragaceae. Tetracarpaea possesses most of the characteristics of an archetypical woody saxifrage, but lacks the unicellular foliar trichomes, hydathodes or glands in the marginal ser rations and a trilacunar, three-trace nodal pattern (Table 3). Tetracarpaea wood is qualitatively similar to the wood of the other escallonioids. The wood of Tetracarpaea dif fers, however, because of the small diameter and short to medium length vessel elements, and the short tracheids com pared to the larger diameter and longer length vessel ele ments, and the long tracheids of the other Escallonioideae. Tetracarpaea also is distinguishable from the Escalloni oideae because of the dark-staining deposits in its ray parenchyma cells. The leaves and nodes of Tetracarpaea are atypical for a woody saxifrage. The leaves have simple craspedodromous venation, and areole development is lacking or incomplete, while the other Escallonioideae studied possess semicraspedodromous venation, and areole development is incomplete to imperfect. The unilacunar, one-trace nodes of Tetracarpaea also contrast with the typically trilacunar, three-trace nodes of the Escallonioideae. Bundle sheaths also do not occur in Tetracarpaea, but are found in all other woo6y saxifrages.

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217 Despite th e similarities in wood anato~y, thes e differ ences in leaf and nodal anatomy argue for the separation of Tetracarpaea from the Escallonioideae. Indeed, Tetracarpaea is isolated among the Saxifragaceae and may belong in its own family. Bauera, like Tetracarpaea, possesses most of the quali tative wood anatomical characteristics of an archetypical woody saxifrage, but its nodal and leaf anatomy differ from that of most woody saxifrages (Table 3). Bauera wood has tracheids, sparse axial xylem parenchyma and homocellular, uniseriate and heterocellular, multiseriate rays as in other woody saxifrages. The presence of radial multiples and clusters of pores and simple perforation plates in the vessel elements, however, separates Bauera from the other woody saxifrages. Bauera also has dark-staining deposits in its ray parenchyma cells, a feature atypical of woody Saxifragaceae. Bauera is unique among all the genera in this study because of its opposite leaves and lateral, foliaceous stip ules. Bauera leaves also are distinctive because of the enlarged, isodiametric tracheids in the vein endings. These and other anatomical differences support the separation of Bauera from the Saxifragaceae, and its placement in either the Cunoniaceae or its own family. Anodopetalum does not fit the anatomical pattern of an archetypical woody saxifrage (Table 3). The opposite leaves with interpetiolar stipules and the trilacunar, three-trace nodal pattern with split lateral traces are not found in the

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218 wood y Sa xif ra ga c eae . T he c omplex pe tiolar v asculature also is aty p ical f o r the wo ody saxifrag e s. The wood of Anodo petalum has clustered por e s and vessel elements with simple perforation plates, whereas, the woody saxifrages typically possess solitary pores and vessel elements with scalariform perforation plates. Anodopetalum is not saxifragaceous and should re m ain in the Cunoniaceae. Aphanopetalum is another genus placed in the Cunonia ceae. The differences outweigh the similarities between Aphanopetalum and the woody Saxifragaceae and argue for the continued exclusion of this genus from the family. Aphano petalum has opposite, stipulate leaves and unilacunar, one trace nodes, while alternate, exstipulate leaves and trila cunar, three-trace nodes are typical for the woody saxi frages. Although the palisade and spongy rnesophyll of the leaves of Aphanopetalum are similar to that in many woody saxifrages, these cells contain dark-staining deposits that are atypical for the woody Saxifragaceae. The taxonomic placement of this genus remains uncertain, especially until the wood can be studied. Donatia is unrelated to the woody Saxifragaceae examined in this study as it does not share many anatomical similarities with other woody saxifrages. The sessile leaves with acrodromous venation and lack of areole develop ment in Donatia contrast with the petiolate leaves with typically semicraspedodromous venation and incomplete to imperfect areole d e velopment in most woody saxifrages.

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219 Donatia also has iso b ilateral lea v es and a large mass of lignified parench y ma cells abaxial to its very small foliar vascular bundles. The leaves of the woody Saxifragaceae are typically dorsiventral and lack a large mass of lignified tissue associated with their vascular bundles. This study shows Donatia to be an isolated genus that probably should be placed in its own family, although the closest relatives of this family remain obscure.

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SUM!vl'..ARY In summary, the present anatomical data: 1. contradict a close relationship among Ixerba, Brexia and Roussea, which are often placed together in the Brexioideae; 2. reveal many similarities between Ixerba and Anopterus in the Escallonioideae; 3. confirm the taxonomic affinity between Cuttsia and Abro phyllum in tribe Cuttsieae of the Escallonioideae; 4. do not support the maintenance of tribe Argophylleae of the Escallonioideae; 5. show Carpodetus to be more similar to Cuttsia and Abro phyllum than to Corokia and Argophyllum; 6. support a close relationship between Corokia and Argo phyllum, however, their taxonomic position remains obscure; 7. validate the combination of the genus Argyrocalymma with Carpodetus and the combination of the genus Colmeiroa with Corokia; 8. show Tetracarpaea, Bauera and Donatia to be distinctive genera, and each genus may warrant a monogeneric family; 9. indicate that while Donatia is isolated, Tetracarpaea is close to Saxifragaceae and Bauera is allied to Cunoniaceae; 10. readily segregate Anodopetalum from the Saxifragaceae and place it in the Cunoniaceae; 11. separate Aphanopetalum from the Saxifragaceae, although its taxonomic position remains obscure. 2 20

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APPENDI X

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N N N Table 4. Specimens of Australasian woody Saxifragaceae examined anatomically. SPECIES COLLECTOR LOCALITY ---------------------Abrophyllum ornans Anodopetalum biglandulosum Anopterus glandulosus Hoogland 11693 F.M. Hueber #1 W.T. Jones 2393 H.C. Hayes s.n. White 10696 Hoogland 11743 Hoogland 11727 Australia Australia Tasmania Tasmania F.M. Hueber 3/17/70 Australia Carlquist 1134 Australia Tasmania Tasmania Tasmania Tasmania ---------XYI.ARIUMa or GARDEN TYP~ OF b MAT ER IA L --------CANBw 7335 Aw H-27147 RBG-Mel.c USw 36041 FPAw 18257 FPAw 31583 MAD-SJRw 19382 FPAw 14002 L,N,W,F L,N,W, F W,D W,D W,S L,N,W, F L,N,W, F L,N,W, F W,D W,D W,D W,D,S w,s

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Table 4--continued. SPECIES -------~nopterus macleayanus Aphanopetalum resinosum Argophyllum cryptophlebum Argophyllum ellipticum Argophyllum nullumense COLLECTOR LOCALITY ---------Hoogland 11651 W.T. Jones s.n. H.C. Hayes Australia Australia Australia Hoogland 11649 Australia F.M. Hueber 3 / 2/70 Australia Hoogland 11801 H.C. Hayes s.n. Australia Australia -----XYLARIUMa or GARD E N TYPE OF MA TE R I A L b -----------CANB 7324 MAD-SJRw 1 5 918 FPAw 17 32 7 Aw 27645 USw 4565 L,N,W, F W,D W,D W, D ,S W, D L,N,F L, N ,W, F w, s W,D L,N,W, F W,D N N w

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Table 4--continued. SPECIES COLLECTOR ----" --------Bauera capitata Bauera rubioides Bauera sessiliflora Carpodetus sp. Carpodetus arboreus Carpodetus major Hoogland 11784 Hoogland 11753 Hoogland 12226 Hoogland 11704 Hoogland 11890 B.F. Shore s.n. 1 Hoogland & Pullen 5582 Saunders 799 ------------LOCALITY Tasmania Australia Victoria Victoria N e w Zealand New Guinea New Guinea New Zealand N e w Zealand XYLARIUMa or GARD E N FPAw 153 3 3 FPAw 17366 NGF 10127d NGF 4768d FPAw H8331 TYPE OF MATERIALb L,N,F L,N,F L,N,F W,D L,N,W,F L,N,F W,D L,N,W,F W,D w,s w, s W,D W,D N N .c:,.

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Table 4--continued. SPECIES COLLECTOR LOCALITY XYLARIUMa TYPE OF or GARDEN MATERIALb S:.l..!"P.2etus major New Guinea FPAw H5582 W,D New Guinea FPAw S799 w,s Caq~odetus serratus w. Philipson #3 New Zealand L,N,W,F Tomlinson 2-I-69 New Zealand L,N,W,F B.F. Shore s.n. 4 New Zealand L,N,F R. Wilson 70/3 New Zealand W,F New Zealand PRFw 1274 W,D New Zealand FPAw 12036 W,D New Zealand FPAw 12071 W,D New Zealand MAD-SJRw 47201 W,D New Zealand MAD-SJRw 25445 W,D Corokia buddleioides L.H. MacDaniels New Zealand MAD-SJRw 25438 W,D I',_) N U1 Corokia caq~odetoides J.D. McCornish 147 Lord Howe Island L,N,D

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Table 4--continued. SPECIES ---------Corokia -c ollenettei Corokia macrocarpa Corokia virgata Corokia whiteana Cuttsia viburnea COLLECTOR J.& T. Clarke R25 R.D. Hoogland & H.C. Hayes s.n. Hoogland 11664 F.M. Hueber #1 F.M. Hueber #2 W.T. Jones s.n. H.C. Hayes Philipson 20404 LOCALITY XYLARIUMa or GARDEN TYPE OF MAT ERI ALb -----------------Rapa Island Chatham Islands New Zealand Australia Australia Australia Australia Australia Australia USw 34143 Kew 118-54-1180le Kew 118-54-1180le MAD-SJRw 55149 CANB 7325 FPAw 20404 FPAw 18202 W,D L,N,F L,N,F W,D L,N,W,F L,N,F L,N,W,F W,D W,D W,D W,D W,D N N er-,

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Table 4--continued. SPECIES Donatia novae-zelandiae Ixerba brexioides COLLECTOR Hoogland 11755 Tomlinson 9-IV-69A w. Philipson #2 B.F. Shore s.n. 2 w. Philipson 249 H.J. Deutzman Cockayne 4978 Kirk 531 LOCALITY Tasmania New Zealand New Zealand New Zealand New Zealand New Zealand New Zealand N e w Z e aland New Zealand New Zealand XYLARIUMa or GARDEN MAD-SJRw 47058 FPAw 14170 wzw 47 Aw 27700 Aw 27699 Aw 20087 FHOw 18961 TYPE OF MATERIALb L,N,F L,N,W,F L,N,F L,N,W,F W,D W,D W,D W,D L,N,S L,N,S w,s w,s l'v l'v -..J

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Table 4--continued. SPECIES Tetracarpaea tasmannica COLLECTOR Hoogland 11745 Hoogland 11738 Comber 2251 LOCALITY Tasmania Tasmania aAbbreviations follow those recommended by Stern (1978c). XYLARIUMa or GARDEN Aw 27721 bL, leaf; N, node; W, wood; F, fluid preservation; D, dried specimen; S, slide cRBG-Mel., Royal Botanic Garden, Melbourne dNGF, Department of Forests, Division of Botany, Lae, New Guinea eKew, Royal Botanic Gardens, Kew, Richmond, Surrey, England TYPE OF MATERIALb L,N,W,F L,N,F w,s N N a,

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LITERATURE CITED Adams, J.E. 1949. the Cornaceae. 244. Studies in the comparative anatomy of J. Elisha Mitchell Sci. Soc. 65: 218Allan, H. H. 1961. Flora of New Zealand, vol. 1. R. E. Owen, Government Printer, Wellington. Arnott, H. J. 1959. Leaf clearings. Turtox News 37: 192-194. Baas, P. 1973. The wood anatomical range in Ilex (Aqui foliaceae) and its ecological and phylogenetic signifi cance. Blumea 21: 193-251. Bailey, F. M. 1883. A synopsis of the Queensland flora. James C. Beal, Government Printer, Brisbane. 1900. The Queensland flora. H. J. Diddams and Co., Queensland. Bailey, I. W. 1944. The development of vessels in angio sperms and its significance in morphological research. Amer. J. Bot. 31: 421-428. 1956. Nodal anatomy in retrospect. 37: 269-287. J. Arnold Arb. Bailey, L. H. 1944. The standard cyclopedia of horticul ture, vol. 1. The Macmillan Company, New York. and Ethel Z. Bailey. 1976. Hortus third. Macmillan Publishing Co., New York. Baillon, H. VO 1. 3. 1872. Saxifragacees. Histoire des plantes, Librairie Hachette and Co., Paris. Beadle, N. C. W. 1981. The vegetation of Australia. Cambridge University Press, Cambridge. ----, O. D. Evans, and R. D. Carolin. 1972. Flora of the Sydney region. A. H. & A. W. Reed Pty. Ltd., Sydney. Bensel, C. R. and B. F. Falser. 1975a. Floral anatomy in the Saxifragaceae sensu lato. I. Introduction, Par nassioideae and Brexioid~ Amer. J. Bot. 62: 176185. 229

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2 30 and---1975b. Floral anato my i n th e Saxifraga ceae sensu lato. III. Kirengesho mo id eae , Hydrangeoi deae and Escallonioid e ae. Am e r. J . Bot. 62: 676-687. and---1975c. Floral anatomy in the Saxifraga ceae sensu 1 a to. IV. Ba ueroideae and con cl us ions. Amer. J. Bot. 62: 688-694. Bentham, G. 1864. Flora Australiensis, vol. 2. Lovell Reeve & Co., London. Bhatnagar, A. K. 1973. studies in Corokia. Morphological and e mb r y ological Botanica (Delhi) 23(4): 149. Bissing, D. R. 1974. Haupt's gelatin adhesive mixed with formalin for affixing paraffin sections to slides. Stain Technol. 49: 116-117. Black, J. M. 1924. Flora of South Australia. Harrison Weir, Adelaide. Brook, J. P. 1951. serratus Forst. 79: 276-285. Vegetative anatomy of Carpodetus Trans. & Proc. Roy. Soc. New Zealand Burbidqe, N. T. 1963. Dictionary of Australian plant genera. Angus and Robertson Ltd., Sydney. Butterfield, B. G. and B. A. Meylan. 1976. The occurrence of septate fibers in some New Zealand woods. New Zealand J. Bot. 14: 123-130. Carey, G. 1938. Comparative anatomy of leaves from species in two habitats around Sydne y . Proc. Linn. Soc. New South Wales 63: 439-450. Carlquist, S. 1961. Comparative plant anatom y . Holt, Rinehart and Winston, New York. 1969. Studies in Stylidiaceae: New taxa, field observations, evolutionary tendencies. Aliso 7: 13-64. 1975. Ecological strategies of xylem evolution. University of California Press, Berkeley. Carolin, R. C. 1960. Floral structure and anatomy in the family Stylidiaceae Swartz. Proc. Linn. Soc. New South Wales 85: 189-196. Chandler, B. 1911. Note on Donatia novae-zelandiae Hook. f. Notes Roy. Bot. Gard. Edinburgh 5(22): 43-47. Cheeseman, T. F. Flora, vol. Wellington. 1914. Illustrations of the New Zealand 1. John Mackay, Government Printer,

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2 31 1925. Manual of th e New Zealand flora. 2nd ed. W. A. G. Skinn er , Govern me nt Printer, Wellington. Committee on Non,enclature, International Association of Wood Anatomists, 1964. Multilingual glossary of terms used in wood anatomy. Verlagsanstalt Buchdruckerei Kon kordia, Winterthur, Switzerland. Cronquist, A. 1968. The evolution and classification of flowering plants. Houghton Mifflin Co., Boston. 1981. An integrated system of classification of flowering plants. Columbia University Press, New York. Cunningham, A. 1839. Florae insularum Novae Zelandiae precursor; or a specimen of the botany of the islands of New Zealand. Ann. Nat. Hist. 3: 244-250. Curtis, Winifred M. 1963. The student's flora of Tasmania, Part 2. L. G. Shea, Government Printer, Tasmania. Dadswell, H. E. and A. M. Eckersley. identification of the principal timbers other than eucalypts. Res. Australia, No. 16. 1935. The commercial Australian Tech. Pap. For. Prod. Dahlgren, R. 1975. A system of classification of the angiosperms to be used to demonstrate the distribution of characters. Bot. Not. 128: 119-147. 1980. A revised system of classification of the angiosperms. Bot. J. Linn. Soc. 80: 91-124. 1983. General aspects of angiosperm evolution and macrosystematics. Nord. J. Bot. 3: 119-149. Davis, G. L. 1966. Systematic embryology of the anqio sperms. John Wiley & Sons, Inc., New York. Dickison, W. C. 1975a. veqetative anatomy. 620. The bases of angiosperm phylogeny: Ann. Missouri Bot. Gard. 62: 5901975b. Floral morpholoqy and anatomy of Bauera. Phvtomorohologv 25: 69-76. 1975c. Leaf anatomy of Cunoniaceae. Bot. J. Linn. Soc. 71: 275-294. 1975d. Studies on the floral anatomy of the Cunoniaceae. Amer. J. Bot. 62: 433-447. 1980a. Comparative wood anatomy and evolution of the Cunoniaceae. Allertonia 2: 281-321.

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232 1980b. Div e rse nodal anatomy of the Cunoniaceae. Amer. J. Bot. 67: 975-981. 1984. Fruits and seeds of the Cunoniaceae. J. Arnold Arb. 65: 149-190. Engler, A. 1890. Saxifragaceae. In: A. Engler and K. Prantl, Die naturlichen Pflanzenfamilien 3(2a): 49-96. 1928. Saxifragaceae. In: A. Engler and K. Prantl, Die naturlichen Pflanzenfamilien, 2nd ed. 18a: 74-226. Erdtman, G. 1952. Pollen morpholoqy and plant taxonomy. Anqiosperms. Almquist and Wiksell, Stockholm. and C. R. Metcalfe. 1963. Affinities of certain genera incertae sedis suggested by pollen morphology and vegetative anatomy. III. The campanulaceous af finity of Berenice arouta Tulasne. Kew Bull. 17: 253256. Eyde, R. H. 1966. Systematic anatomy of the flower and fruit of Corokia. Arner. J. Bot. 53: 833-847. Fairbrothers, D. E. 1977. Perspectives in plant sero taxonomy. Ann. Missouri Bot. Gard. 64: 147-160. ----, T. J. Mabry, R. L. Scogin and B. L. Turner. 1975. The bases of angiosperm phylogeny: Chernotaxonomy. Ann. Missouri Bot. Gard. 62: 765-800. Ferguson, I. K. and M. J. Hideux. 1978. Some aspects of the pollen morpholoqy and its taxonomic significance in the Cornaceae sens. lat. In: Proc. IV Internat. Palynol. Conf. Lucknow,~dia-1: 240-249. Forster, J. R. and G. Forster. 1776. Characteres generum plantarum, quas in itinere ad insulas maris australis collegerunt, descripserunt, delinearunt annis 17721775. B. White, T. Cadel 1, & P. Elmlsy, London. Gardner, R. O. 1978. Systematic notes on the Alseuosmia ceae. Blumea 24: 138-142. Graaf, N. A. van der and P. Baas. 1974. Wood anatomical variation in relation to latitude and altitude. Blumea 22: 101-121. Harms, H. 1897. Cornaceae. In: A. Engler and K. Prantl, Die naturlichen Pflanzenfamilien 3(8a ): 250-270. Harrar, E. S. 1946. fiber-tracheids. Notes on starch grains in septate Trop. Woods 85: 1-9.

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233 Hickey, L. J. 1979. A re v ised classification of the archi tecture of dicotyledonous leaves. In: C.R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyledons, 2nd ed., vol. 1, pp. 25-39. Clarendon Press, Oxford. Hideux, M., and I. K. Ferguson. 1976. The stereostructure of the exine and its evolutionary significance in Saxifragaceae sensu lato. In: I. K. Ferguson and J. Muller (eds.), The evolutionary significance of the exine. Linn. Soc. Symposium Series 1: 327-377. Holle, G. 1893. Beitrage zur Anatomie der Saxifragaceen und deren systematische Verwerthung. Bot. Centralbl. 53: (1) 1-9; (2) 33-41; (3) 65-70; (4) 97-102; (5) 129-136; (6) 161-169; (7 / 8) 209-222. Hooker, J. D. 1865. Saxifraoeae. In: G. Bentham and J. D. Hooker, Genera plantarum, voll., po. 629-655. Lovell Reeve and Company, London. Reprint. Verlaa von J. Cramer, Weinheim, 1965. 1867. Cornaceae. In: G. Bentham and J. D. Hooker, Genera nl an ta rum:vol 1., pp. 9 4 7-9 5 2. Lovel 1 Reeve and Company, London. Re n rint. Verlag von J. Cramer, Weinheim, 1965. Hooker, W. J. 1840. Icones olantarum. vol. 3. Longman, Orme, Brown, Green and Lonomans, London. Howard, R. A. 1979a. The stem-node-leaf continuum of the Dicotvledoneae. In: C. R. Metcalfe and L. Chalk, (eds.), Anatomy oTthe dicotvledons, 2nd ed., vol. 1, pp. 76-87. Clarendon Press, Oxford. 1979b. The petiole. In: C.R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyledons, 2nd ed., vol. 1, pp. 88-96. Clarendon Press, Oxford. Hutchinson, J. 1967. The genera of flowering plants. Dicotyledones, vol. 2. Clarendon Press, Oxford. Ingle, H. D., and H. E. Dadswell. 1956. The anatomy of the timbers of the south-west Pacific area. IV. Cunonia ceae, Davidsoniaceae, and Eucryphiaceae. Austral. J. Bot. 4: 125-151. Johansen, D. A. 1940. Plant microtechnique. McGraw-Hill, New York. Kapil, R. N. and A. K. Bhatnaqar. and floral parts of Corokia. 257-266. 1974. Stomata on leaves Bot. Jahrb. Syst. 94: Krach, J. E. 1976. Samenanatomie der Rosifloren: 1. Die 1-6 0. Sa men der Saxi fragaceae. Bot. Jahrb. Syst. 9 7:

PAGE 250

2 3 4 1977. Seed characters in and affinities a m ong the Saxif ragineae. Plant Sys t. Evol., Suppl. 1: 141-15 3. Labillardiere, J.-J. 1804. Novae Hollandiae plantarum specimen, vol. 1. D. Huzard, Parisiis. Laing, R. M. and E.W. Blackwell. [1949]. Plants of N e w Zealand, 5th ed. Whitcombe and Tombs Limited, Christchurch. Li, H.-L. and C.-Y. Chao. 1954. Comparative anato m y of the woods of Cornaceae and allies. Quart. J. Taiwan Mus. 7: 119-136. Lubbock, J. 1894. function. II. On the stipules, their form and J. Linn. Soc. Bot. 30: 465-532. Mcclintock, E. 1957. A monograph of the genus Hydrangea. Proc. Calif. Acad. Sci. 29: 147-256. Melchior, H. 1964. Cornaceae. In: H. Melchior, A. Engler's S y llabus der Pflanzenfamilien, vol. 2, pp. 369-370. Gebruder Borntraeger, Berlin. Metcalfe, C. R. 1979. The leaf: General topography and ontogeny of the tis sues. In: C. R. Metca 1 f e and L. Chalk, (eds.), Anatomy of the dicotyledons, 2nd ed., vol. 1, pp. 63-75. Clarendon Press, Oxford. 1983. Secreted mineral substances. In: C. R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyle dons, 2nd ed., vol. 2. Clarendon Press, Oxford. and L. Chalk. 19 50. Anatomy of the dicotyledons, 2 Oxford. vols. Clarendon Press, and 1979. Anatomy of the dicotyledons, vol. 1, 2nd ed. Clarendon Press, Oxford. and 1983. Anatomy of the dicotyledons, vol. 2, 2nd ea. Clarendon Press, Oxford. Meylan, B. A. and B. G. Butterfield. 1978. Occurrence of helical thickenings in the vessels of New Zealand woods. N e w Phytol. 81: 1 3 9-146. Mildbraed, J. 1907. Stylidiaceae, Heft 35. In: A. Engler, Das Pflanzenreich, 4. 278: 1-98. Morrison, T. M. 1953. Comparative histology of secondary xyle m in buried and exposed roots of dicotyledonous trees. Phytomorphology 3: 427-430.

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2 35 Mosley, J. G. (compiler). 1974a. Conservation in South Australia. In: R. L. Specht, Ethel M. Roe, and Valerie H. Boughton, (eds.), Conservation of major plant communities in Australia and Papua New Guinea. Austral. J. Bot., Suppl. 7: 236-318. 19 7 4b. Conservation in Tasmania. In: R. L. Specht, Ethel M. Roe, and Valerie H. Boughton, (eds.), Conservation of major plant communities in Australia and Papua New Guinea. Austral. J. Bot., Suppl. 7: 319448. Mueller, F. von. 1862. Brachynema. Fraqmenta phytograph iae Australiae, vol. 3. [Joannis Ferres], Melbourne. 1865. Cuttsia. Australiae, vol. 5. Fragmenta phytographiae [Joannis Ferres], Melbourne. 1879. Sopra la posizione sistematica del genre Donatia. Nuovo Giorn. Bot. Ital. 10: 201-203. Oever, L. van der, P. Baas and M. Zandee. 1981. Compara tive wood anatomy of Symplocos and latitude and alti tude of provenance. IAWA Bull. n.s. 2: 3-24. Ohtani, J., B. A. Meylan and B. G. Butterfield. 1983. Oc currence of warts in the vessel elements and fibers of New Zealand woods. New Zealand J. Bot. 21: 359-372. Patel, R. N. 1973a. Wood anatomy of the dicotyledons indigenous to New Zealand: 1. Cornaceae. New Zealand J. Bot. 11: 3-22. 1973b. Wood anatomy of the dicotyledons indigenous to New Zealand: 2. Escalloniaceae. New Zealand J. Bot. 11: 4 21-4 3 4 Philipson, W. R. 1967. Griselinia Forst. fil.--Anomaly or link. New Zealand J. Bot. 5: 134-165. 1974. Ovular morphology and the major classifica tion of the dicotyledons. Bot. J. Linn. Soc. 6: 89108. and M. N. Philipson. 1973. A comparison of the em bryology of Forstera L. and Donatia J. R. & G. Forst. New Zealand J. Bot. 11: 449-459. Prakash, N. and E. J. McAlister. 1977. An embryological study of Bauera capitata with comments on the systemat ic position of Bauera. Austral. J. Bot. 25: 615-622.

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2 36 Ramamonjiarisoa, Bakolimalala A. 1980. Comparativ e anatomy and syste m atics of African and Malagas y woody Saxifra gaceae sensu lato. Ph.D. Diss. Un iversity of Massachus e tts~ Amherst. Rapson, L. J. 1953. Vegetative anato my in Donatia, Phyl lachne, Forstera and Oreostylidi um and its taxonomic significance. Trans. & Proc. Ro y . Soc. New Zealand 80: 399-402. Raven, P.H., and D. I. Axelrod. 1972. Plate tectonics and Australasian oaleobiogeography. Science 176: 13791386. Reeder, J. R. 19 4 6. Notes on Pa puas ian Saxi f raoaceae. J. Arnold Arb. 27: 275-288. Robinson, D. E. and J. K. Grigor. 1963. The origin of oeriderm in some New Zealand olants. Trans. Rov. Soc. New Zealand, Bot. 2: 121-124. Sampson, F. B. and J. McLean. 1965. A note on the occur rence of dornatia on the under side of leaves in New Zealand plants. New Zealand J. Bot. 3: 104-112. Schlechter, R. 1914. Die Saxifraqaceae Papuasiens. Bot. Jahrb. Syst. 52: 118-138. Schu 1 ze-Menz, G. K. 19 64. Saxi f raqaceae. In: H. Melchior, A. Engler's Syllabus der Pflanzenfamilien, vol. 2, pp. 201-206. Gebruder Borntraeger, Berlin. Sertorius, A. 1893. Beitrage zur Kenntnis der Anatomie der Cornaceae. Bull. Herb. Boissier 1: 469-484, 496-512, 551-570, 614-639. Sinnott, E.W., and I. w. Bailey. 1914. Investigations on the phylogeny of the angiosperms. III. Nodal anatomy and the morpholoqy of stipules. Amer. J. Bot. 1: 441453. Skottsberg, C. 1915. Notes on the relations between the floras of Subantarctic America and New Zealand. Pl. World 18: 129-142. Small, J. K. and P. A. Rydberg. North American Flora 22: 1905. Hydranoeaceae. 159-1 78. Smith, L. S. 1958. Corokia A. Cunn. An addition to the Australian genera of Saxi f ragaceae. Proc. Roy. Soc. Queensland 69: 53-55.

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237 Solereder, H. 1908. Sy s tematic an a to my of the dicotyle dons, 2 vols. Translateo by L.A. Boodle and F. E. Fritsch. R ev ised by D. H. Scott. Clarendon Press, Oxford. Stearn, w. T. 1965. Bentham and Hooker's Genera plantarum: Its history and dates of publication. In: G. Bentham and J. D. Hooker, Genera plantarum, vol. 1, pp. ii-ix. Reprint. Verlag von J. Cramer, Weinheim. Stern, W. L. 1974a. Comparative anatomy and s y stematics of woody Saxifraqaceae. Escallonia. Bot. J. Linn. Soc. 68: 1-20. 1974b. Saxifragales. Encyclopaedia Britannica, 15th ed., vol. 16, pp. 291-302. Encvclopaedia Britan nica, Inc., Chicaqo. 1978a. Comparative anatomy and systematics of woody Saxifragaceae. Hydrangea. Bot. J. Linn. Soc. 76: 83-113. 1978b. A retrospective view of comparative anat omy, phylogeny, and plant taxonomy. IAWA Bull. 2: 3339. 1978c. Index xylariorum. 2. Taxon 27: 233-269. ---, G. K. Brizicky and R. H. Evde. 1969. Comparative anatomy and relationships of Columelliaceae. J. Arnold Arb. 50: 36-75. ----, E. M. Sweitzer and R. E. Phipps. 1970. Compara tive anatomy and systematics of woody Saxifraqaceae. Ribes. Eat. J. Linn. Soc. 63, Suppl. 1: 215-237. Styer, C. H. 1978. Comparative anatomy and systematics of woodv Saxifragaceae. Ph.D. Diss. University of Maryland, College Park. ---and W. L. Stern. 1979a. Comparative anatomy and systematics of woody Saxifraqaceae. Philadelphus. Bot. J. Linn. Soc. 79: 267-289. and W. L. Stern. 1979b. Comparative anatomy and systematics of woody Saxifraqaceae. Deutzia. Bot. J. Linn. Soc. 79: 291-319. Swamy, B. G. L. 1954. Morpho-taxonomical notes on the Escallonioideae, Part A. Nodal and petiolar vascula ture. J. Madras Univ. 24: 299-306. Synqe, P. M. (ed.). 1974. The Royal Horticultural Society dictionary of gardeninq, 2nd ed., vols. 1 and 2. Clarendon Press, Oxford.

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2 38 Takhtajan, A. 1966. toru m . "Nauka," Systema et Ph y logenia Magnoliophy Moscow and Leningrad. ( In Russian) 1980. Outline of the classification of flowering 'plants (Maqnoliophyta). Bot. Rev. 46: 225-359. 1983. The systematic arrangement of dicotyledonous families. In: C.R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyledons, 2nd ed., vol. 2, pp. 180201. Clarendon Press, Oxford. Theobald, W. L., J. L. Krahulik, and R. C. Rollins. 1979. Trichome description and classification. In: C. R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyle dons, 2nd ed., vol. 1, pp. 40-53. Clarendon Press, Oxford. Thorne, R. F. 1976. A phylogenetic classification of the Evol. Biol. 9: 35-106. Angiospermae. 1983. Proposed new realignments in the angio sperms. Nord. J. Bot. 3: 85-117. Thouvenin, M. ,, fragacees. 1890. Recherches sur la structure des Saxi Ann. Sci. Nat. Bot. (7e ser.) 12: 1-174. Tippo, o. 1938. Comparative anato my of the Moraceae and their presumed allies. Bot. Gaz. 100: 1-99. 1941. A list of diagnostic characteristics for descriptions of dicotyledonous woods. Trans. Illinois State Acad. Sci. 34: 105-106. Tyler, A. A. 1897. The nature and origin of stipules. Ann. New York Acad. Sci. 10: 1-49. Wageni tz, G. 19 64. Styl idi aceae. In: H. Mel chi or, A. Engler's Syllabus der Pflanzenfamilien, vol. 2, pp. 483-484. Gebruder Borntraeqer, Berlin. Watari, S. 1939. Anatomical studies on the leaves of some saxifraoaceous plants, with special reference to the vascular system. J. Fae. Sci. Univ. Tokyo, Sect. 3, Bot. 5: 195-316. Wakabayashi, M. 1970. On the affinitv in Saxifragaceae s. lato with special reference to oollen morohologv. Acta Phvtotax. Geobot. 2 4: 128-14 5. Weiss, A. 1890. Untersuchunoen uber die Trichome von Corokia buddleioides Hort. Sitzungsber. Kaiserl. Akad. Wiss., Math.-Naturwiss. Cl., Abt. 1 99: 268-282.

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--------2 3 9 Wilkinson, H. P. 1979. The plant surface {mainl y leaf). In: C.R. Metcalfe and L. Chalk, (eds.), Anatomy of the dicotyledons, 2nd ed., vol. 1, pp. 97-165. Claren don Press, Oxford. Willis, J. C. 1973~ A dictionary of the flowering plants and ferns. stu ed. (revised by H.K. Airy Shaw). Cambridge University Press, Cambridge. Willis, J. H. 1972. A handbook to plants in Victoria. Melbourne University Press, Melbourne. Willis, M. 1949. By their fruits: Mueller. Angus and Robertson, A life of Ferdinand von Sydney. Zemann, Margarete. 1907. Studien zu einer Monographie der Gattunq Argophyllum Forst. Ann. K. K. Naturhist. Hofmus. 22: 270-292.

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BIOGRAPHICAL SKETCH Matthew Henry Hils was born in Chattahoochee County, Georgia, on 27 November 1955 to M. David Hils and Elizabeth J. Hils (Oberle). He attended parochial schools in Cincinnati, Ohio, and was graduated from LaSalle High School in 1974. He received a B.A. in biology from Thomas More College in 1978 and an M.S. in botany from Miami University in 1980. He began his studies at the Univesity of Florida in September of 1980. He has been a research assistant and teaching assistant throughout his qraduate schooling. He also has worked as a laboratory technician for the U.S. Environmental Protection Aqency and as a botanist for both the U.S. Department of Aqriculture and the Ohio Department of Natural Resources. He married Wendy E. Mahon on 30 October 1982. He has been a visiting assistant professor in the Department of Biology at Hiram Colleqe in Hiram, Ohio, since September, 1984. 240

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I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Te~. ~~~~f't,,;;-Associate Professor of ho~~ny I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. __ Assistant Professor of Botany I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Resources and Conservation I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation for the degree of Doctor of Philosophy. Associate Professor of Botany I certify that I have read this study and that in my opinion it conforms to acceptable standards of scholarly presentation and is fully adequate, in scope and quality, as a dissertation fr the degree of Doctor of Philosophy . .__..~w~i ITI~;-LO~~ Professor of Bot y

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This dissertation was submitted to the Graduate Faculty of the Departrnen t of Botany in the Co 11 ege of Libera 1 Arts and Sciences and to the Graduate School, and was accepted as partial fulfillment of the requirements for the degree of Doctor of Philosophy. August 1985 Dean for Graduate Studies and Research

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