|Table of Contents|
Chapter 1. Introduction
Chapter 2. Anatomical and morphological study
Chapter 3. Epicuticular wax study
Chapter 4. Cladistic analysis
Chapter 5. Discussion
SYSTEMATIC SURVEY OF CORYPHOID PALMS USING FOLIAR
EPICUTICULAR WAX AND ANATOMICAL CHARACTERS
YOLANDER RENEA TAYLOR
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
Yolander Renea Taylor
I am grateful to several people for the completion of
this work. The research staff of the Fairchild Tropical
Garden provided access to the extensive palm collection of
this garden. The SEM work was in part supported by funds
provided by the Botany Department and was conducted in the
Electron Microscopy Core Laboratory, Interdisciplinary
Center for Biotechnology Research, University of Florida,
Gainesville, Florida. Norris Williams, Mark Whitten, Wesley
Higgins and the Molecular Systematics Laboratory were ever
so gracious in allowing me to use their computers and
programs. My committee members Walter S. Judd, Scott Zona,
William L. Stern, Henry A. Aldrich, and David A. Jones were
always readily available to me during my tenure here. I
thank each one of them for helping me and guiding my
research. My fellow graduate students have also been
supportive, especially Kim Gulledge, Nico Cellense, and Reed
Last, but not least I thank my family. They have been
my rock. Their support has guided me throughout all my
endeavors. This work is dedicated to them, especially my
brother, who provided photographic support, and my mother,
TABLE OF CONTENTS
ACKNOWLEDGEMENTS .......................................................................................................... iii
A B S T RA C T ................................................................................................................................. v
I INTRODUCTION ................................................................................................... 1
Geographical Distribution ................................................................. 4
Morphological Characteristics of Palms ........................... 8
Current Classifications .................................................................... 15
Foliar Anatomy ................................................................................................... 16
Foliar Epicuticular Waxes ................................................................. 21
Research Objectives ..................................................................... 25
II ANATOMICAL AND MORPHOLOGICAL STUDY ....................................... 27
Introduction .................................................................................................. 27
Methods .................................................................................................................. 27
Character List .................................................................................................. 35
III EPICUTICULAR WAX STUDY .................................................................... 65
Introduction ................................................................................................... 65
Methods .................................................................................................................. 67
Epicuticular Wax Characters ..................................................... 68
IV CLADISTIC ANALYSIS ....................................................................................... 84
Cladistic analysis based on anatomical and
Epicuticular Wax Data ........................................................... 84
Combined Cladistic Analysis Based on Morphological
Anatomical, and Micromorphological Data ......... 108
Combined Cladistic Analysis Based on Anatomical,
Micromorphological and Morphological Data ...... 120
V DISCUSSION ............................................................................................................ 148
LITERATURE CITED ...................................................................................................... 155
BIOGRAPHICAL SKETCH ................................................................................................ 161
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
SYSTEMATIC SURVEY OF THE CORYPHOID PALMS USING FOLIAR
EPICUTICULAR WAX AND ANATOMICAL CHARACTERS
Yolander Renea Taylor
Chairman: Walter S. Judd, Ph.D.
Major department: Botany
Foliar epicuticular wax structures/patterns can provide
useful taxonomic characters. Use of the Scanning Electron
Microscope to view the epicuticular wax layer of palm leaves
allowed qualitative wax features to be readily
characterized. These characters were used in a cladistic
study of palms (Arecaceae), with an emphasis on the
Coryphoideae. These characters were used in order to expand
the number of phenotypic characters available for analysis.
It was found that epicuticular wax characters such as
crusts/layers and rods do help support the monophyly of
certain groups within the palms, e.g., the Coryphoideae and
Borasseae. However, these characters are often quite
homoplasious, as are many other morphological characters,
and therefore, they should not be used alone in a cladistic
study. Instead, they should be combined with numerous other
phenotypic and/or molecular features (as was done here). In
the analyses performed as part of this investigation certain
aspects of the current classification of Arecaceae are not
supported. The monophyly of Ceroxyloideae, Arecoideae, and
Calamoideae was called into question. The Coryphoideae are
indicated as monophyletic, but the large tribe Corypheae is
definitely non-monophyletic because Coryphinae and
Borassaeae form a well supported clade. Analysis of
combined data sets (e.g., epicuticular wax, vegetative
anatomy, morphology, and DNA) are shown to provide increased
resolution of infrafamilial clades.
Palms epitomize the monocots with their leaves and
sheathing leaf bases, parallel foliar venation, and
trimerous flowers (Uhl & Dransfield, 1987). Their most
obvious features, the coriaceous, plicate leaves and
arborescent habit, characterize the group. Leaves of palms
may be palmate, costapalmate, or pinnate (Figure 1-1), and
borne at the apex of a woody trunk. Palm inflorescences are
typically variously branched spikes, often with expanded
bracts. The fruits are drupes. Monophyly of the group is
well supported by morphological and molecular features
(Chase et al., 1995; Uhl & Dransfield, 1987; Uhl et al.,
1995; Zona, 1997).
Palms are among the most variable plants in the world.
They have a long cultural, medicinal, and commercial history
(Balick, 1986; Henderson, 1990; Hill, 1952; Morton, 1977;
The palm family is pantropical with subtropical
extensions. The extreme limits of distribution are 44 N
latitude in Europe and 44 S latitude on the Chatham
Islands, near New Zealand (Corner, 1966). They are mainly
found in humid tropical areas, although few species do
Figure 1-1. Three characteristic palm leaf types (Uhl &
I, D tiO
venture into temperate regions but rarely do they become
established in deserts. Present limits of the family mark
the line where frost damage to living tissue becomes serious
enough to impede growth in competition with other vegetation
Palms once had a much wider distribution than they do
now (Corner, 1966). The fossil record indicates that palms
were found in what today are unlikely places, including the
Arctic and subarctic zones (Uhl & Dransfield, 1987). In
North America, palm fossils from the Cretaceous period have
been found in Colorado, Alaska, Vancouver Island, Oregon,
South Carolina and possibly New Mexico during the Cretaceous
period (Uhl and Dransfield, 1987). Fruits and seeds have
also been discovered in the London Clay bed and Greenland
(Uhl and Dransfield, 1987). The climate in these areas
during the Cretaceous and early Tertiary was apparently much
more tropical than it is today and thus more conducive to
The earliest recorded palm fossils are the Coryphoid
palms Sabal magothiensis (Berry, 1911) and Palmoxylon
cliffwoodensis (Berry, 1916), which occurred in the
Santonian period of the Upper Cretaceous (Uhl & Dransfield,
1987). The earliest fossil pollen records of palms are of
Nypa and date from the Maestrichtian period (Dahglian,
1981). Palms are probably the most abundant monocots found
in the fossil record (Dahglian, 1981; Herendeen and Crane,
1995), possibly because of their tough leaves and woody
stems. Palms became more numerous and abundant during the
Eocene period, a time of widespread tropical forests, but
were more limited during the Oligocene as climatic changes
occurred. The fossilized palm fruits found in Eocene and
Oligocene deposits resemble the genera Sabal, Serenoa,
Livistona, Trachycarpus, and Nypa. During cooling in the
Miocene and Pliocene there was a gradual retreat of palms to
their present locations in tropical and subtropical
latitudes (Axelrod, 1950).
The present day disjunct distribution of palms was
probably greatly influenced by the break-up of Laurasia and
Gondwanaland and the subsequent colliding of land fragments.
Many palms are endemic and show very restricted or disjunct
distributions. Most palms, with the exception of Nypa and
Cocos do not have fruits suited for long distance dispersal
without animal intervention, yet many genera have wide gaps
in their geographical ranges (Zona and Henderson, 1989).
Evidence suggests that these restricted distributions,
disjunctions, and large gaps in ranges of genera are
probably the result of climatic changes (mainly involving
temperature fluctuations and hydrological conditions) and
the movement of land masses (Uhl & Dransfield, 1987).
Six subfamilies are usually recognized, distributed as
Coryphoideae consist of three tribes: Corypheae are
pantropical and subtropical; Phoeniceae are Old World
tropical and subtropical; and Borasseae are found on
landmasses adjoining the Indian Ocean (Uhl & Dransfield,
1987). Corypheae and Phoeniceae traditionally are
considered to be the least specialized members of the
subfamily and are thought to be Laurasian in origin. The
Borasseae, are more specialized and believed to have a
Gondwanaland origin (Uhl & Dransfield, 1987).
Three tribes comprise the Calamoideae: Calameae are
presently found in Asia, Central and South America, and
Africa; Lepidocaryeae occur mostly in northern South
America. Uhl & Dransfield (1987) proposed that early
radiation of Calamoid ancestors occurred in northern
Gondwanaland followed by dispersal to Southeast Asia along
the shores of the Tethys Sea. Then representatives of the
group are thought to have dispersed to South America before
its separation from Africa; this dispersion was followed by
extinction of many taxa in Africa in relatively recent
Nypoideae occur today in Southeast Asia and the western
Pacific islands. Fruits of Nypa are well adapted for
dispersal by ocean currents. The fossil record indicates
that Nypa was once found in Europe, North and South America
and Australia. The genus probably has a Laurasian origin
because it was frequent along the Tethys shores (Uhl &
Ceroxyloideae comprise three tribes: Cyclospatheae are
endemic to the Caribbean; Ceroxyleae and Hyophorbeae have
disjunct austral distributions. The breakup of Gondwanaland
may explain the current disjunct distribution of this
subfamily (Uhl & Dransfield, 1987).
Arecoideae are divided into six tribes and constitute
the largest subfamily of palms. The origin and dispersal
patterns of this group are uncertain. The center of
distribution for Caryoteae is in Southeast Asia and
Indochina. Iriarteae may have a South American origin
because only a few taxa occur outside of this continent.
Podococceae are restricted to the tropical rainforests of
Africa. It is believed that there were more kinds of palms
in Africa in the past, but many became extinct due to
Pleistocene climatic changes (i.e., repeated periods of
aridity) which have affected that continent. Areceae are
found in the Americas, West Africa, Madagascar, India and
Nicobar Islands, Papuasia, the Mascarene Islands, Seychelles
Islands, Sri Lanka, Malesia, and the Philippines. Cocoeae
are found in the Americas, equatorial and southern Africa,
the Pacific region, and Madagascar. Present day
distributions may suggest an origin in West Gondwanaland
with subsequent radiation in the Americas. Geonomeae occur
in Mexico, Central to South America, and the Caribbean.
SYSTEMATIC SURVEY OF CORYPHOID PALMS USING FOLIAR
EPICUTICULAR WAX AND ANATOMICAL CHARACTERS
YOLANDER RENEA TAYLOR
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
apparatus. All except silica bodies and ultraviolet
absorbing compounds are probably synapomorphies.
Palms are trees, shrubs, or lianas, with erect or
prostrate, usually unbranched stems; their roots are
mycorrhizal (Zomlefer, 1994). Leaves of palms are large,
simple to palmately or pinnately compound, plicately folded,
and often have a hastula (Fig. 1-1). Generally palm leaf
segments will have either induplicate or reduplicate
plications. The leaves may be palmate, costapalmate or
pinnate (Fig. 1-1). Induplicate palms are restricted to the
Coryphoideae and the tribe Caryoteae (of Arecoideae). All
other palm groups have reduplicate plications (Uhl &
Inflorescences of palms are determinate and often
paniculate to compound-spicate. Prophylls are always
present and may be numerous to few and small to very large.
Inflorescence bracts may also vary in number and are
sometimes enlarged and woody (Zomlefer, 1994).
Palm flowers are actinomorphic, perfect or imperfect,
hypogenous, usually sessile, and usually small. The calyx
is ordinarily composed of three distinct to connate,
imbricate, and often persistent sepals. The corolla
comprises three petals, which are distinct to connate,
leathery or fleshy, and usually inconspicuous. The
androecium contains six, biseriate stamens, but sometimes
they are numerous (due to a secondary increase). Filaments
are distinct to variously connate and/or adnate to the
petals; anthers are basifixed or dorsifixed, and dehisce by
The gynoecium is generally apocarpous (may also be
psuedomonomerous), one to three carpellate, or syncarpous to
three carpellate; the ovary is usually superior, with basal,
axile, or apical placentation. One to three styles may be
present and the stigmas are erect or recurved. Fruits are
drupes or nutlike structures, with a fleshy, fibrous, or
leathery mesocarp; there are usually one to three (i.e., one
per carpel) and the endosperm is copious, homogeneous or
ruminate, and oily or occasionally hard; the embryo is
minute (Moore, 1976; Uhl & Dransfield, 1987; Zomlefer, 1994;
Stems of palms contain peripheral apical meristems,
which are largely responsible for growth in width
(Tomlinson, 1990). The tissues have tannins, raphides and
silica (Tomlinson, 1990). Epicuticular waxes are present
and generally are of the Strelitzia-type as described later
(Barthlott and Frolich, 1983).
Characteristics of the subfamilies of palms as noted by
Uhl et al.(1987) are summarized below:
Coryphoideae are hermaphroditic, dioecious,
polygamodioecious, or polygamonoecious, but never strictly
monoecious. Their leaves are usually palmate or
costapalmate, rarely undivided or pinnate, and plication is
almost always strictly induplicate. Interfold splits occur
in three genera, and the plication is reduplicate in
Guihaia. Flowers are solitary or in cincinni, but are never
borne in triads (i.e., a cluster with a central pistillate
flower and two lateral staminate flowers). The flowers have
three sepals, three similar petals, six stamens in two
whorls of three, and three, free to variously connate
Members of the Phoeniceae have pinnate leaves and basal
leaflets modified as spines. Leaves of Corypheae are
palmate or costapalmate. The plants are usually
hermaphroditic, or polygamodioecious, rarely strictly
dioecious. If the plants are dioecious, the flowers are not
dimorphic. Rachillae lack deep pits and the endocarps are
usually thin, crustaceous or cartilaginous. Leaves of
Borasseae are palmate or costapalmate. Plants are dioecious
with strongly dimorphic flowers, and the staminate and
sometimes the pistillate flowers are borne in deep pits
formed by connation and adnation of rachilla bracts. The
endocarp is very thick and hard (Uhl & Dransfield, 1987).
Members of Calamoideae are easily distinguished by
their distinctive fruits, which contain overlapping scales
usually arranged in neat rows (Uhl & Dransfield, 1987).
Plants are hermaphroditic, monoecious, dioecious, or
polygamous. They are often fiercely armed. Leaves are
pinnate, or less commonly palmate and reduplicate. The
inflorescence is often highly branched, and parts are
frequently adnate. Bracts are usually tubular with flowers
that are almost always borne in dyads or dyad derivatives.
Unisexual flowers are only slightly dimorphic. The ovary
and fruit, as mentioned above, are covered with overlapping,
recurved scales (modified hairs). The ovary is incompletely
trilocular with basal anatropous ovules and micropyles
facing the center of the gynoecium. The pericarp is usually
thin at maturity, with an undifferentiated endocarp. One to
three seeds are usually produced, and each has a thick
sarcotesta. Calameae have pinnate leaves; Lepidocaryeae
have palmate or shortly costapalmate leaves Uuhl and
Nypoideae are monoecious. Stems are prostrate with
dichotomous branching, leaves are pinnate and plication is
reduplicate. A pistillate head with lateral branches ending
in short spikes of staminate flowers terminates the
inflorescence. Flowers are extremely dimorphic. Six linear
distinct perianth parts are present and similar in plants of
both sexes. Three stamens are present, united in a column.
Three, free irregularly polyhedric carpels are curved and
angled with a funnel-shaped stylar opening. The fruiting
head is large, globose, and composed of irregularly
compressed and enlarged carpels with or without seeds. This
subfamily contains only the species Nypa fruticans, a
mangrove palm (Uhl & Dransfield, 1987).
Ceroxyloideae contain tall, moderate, or small,
solitary or clustered unarmed plants. They are
hermaphroditic, monoecious, or dioecious. The leaves are
regularly or irregularly pinnate and reduplicate.
Crownshafts may or may not be present. The inflorescence
contains three prophylls and usually several peduncular
bracts. When flowers are unisexual, they are only slightly
dimorphic. The gynoecium is syncarpous and triovulate.
Bisexual flowers borne on stalks characterize the
Cyclospatheae. Ceroxyleae are dioecious with unisexual
flowers borne singly on short stalks. Flowers of
Hyophorbeae are unisexual and sessile (Uhl and Dransfield,
Arecoideae are monoecious. Leaves are pinnate and
plication is reduplicate (or rarely induplicate in
Caryoteae). The flowers are borne in triads with a central
pistillate flower with two staminate ones. The group
contains six tribes: Caryoteae, Iriarteeae, Geonomeae,
Areceae, and Cocoeae (Uhl & Dransfield, 1987). Caryoteae
frequently show basipetal production of flowers. Leaves are
pinnate or doubly pinnate, and plication is induplicate.
The inflorescences are sometimes bisexual or unisexual due
to reduction of the triads. In the Iriarteeae the leaves
are also pinnate and plication is reduplicate. The flowers
are sessile. In the Podococceae the inflorescences are
spicate with flowers in sunken pits. The leaves of members
of this group are pinnate and plication reduplicate. The
Geonomeae also have pinnate leaves, reduplicate plication
and flowers sunken in pits (on rachillae). The petals of
staminate and pistillate flowers are basally connate and
form a soft tube. In Areceae the gynoecium is usually
pseudomonomerous (but very rarely triovulate). When
triovulate, the fruit is usually only 1-seeded. Leaves are
pinnate and reduplicate; a crownshaft is sometimes present.
In Cocoeae, as in other arecoid palms, leaves are pinnate
and plication is reduplicate, and flowers have a trilocular
and triovulate gynoecium. The fruit has a thick and bony
endocarp, usually provided with three pores; the
inflorescence is associated with a large persistent and bony
bract (Uhl & Dransfield, 1987).
Phytelephantoideae are moderate to rather large and
acaulescent or erect unarmed dioecious palms. Leaves are
pinnate and plication is reduplicate and inflorescences are
markedly dimorphic. The prophyll is rather short and
usually obscured by the leaf sheath, with one peduncular
bract. The staminate inflorescence is headlike, with
multiparted flowers, and a reduced perianth but numerous
stamens. Pistillate flowers are solitary and crowned with a
perianth of elongate fleshy sepals. The fruits are 5-10-
seeded and borne in a congested headlike cluster. The
mesocarp cracks to form irregular, fibrous, pyramidal warts.
The seed, with its hard endosperm, is enclosed in a hard,
thin, smooth, pyrene (Uhl & Dransfield, 1987).
Arecaceae are diagnosed by the series of shared
characters, as mentioned previously. Traditionally, palms
were thought to be related to Pandanaceae, Cyclanthaceae,
and Araceae. Bentham & Hooker (1883) placed them between
Juncaceae and Cyclanthaceae. Pandanaceae and Cyclanthaceae
are also woody and share with palms the arborescent habit,
large and sometimes plicate leaves, and rather small, drab
flowers. Of course, Araceae are herbs or vines. It has
since been shown that palms are only superficially similar
to Araceae, Cyclanthaceae, and Pandanaceae (Chase et al.,
1993; Duvall et. al, 1993). They differ because palms do
not have compound vascular bundles while, Pandanaceae and
Cyclanthaceae do. Arecaeae have Strelitzia-type waxes while
the Pandanaceae, Cyclanthaceae, and Araceae have various
other wax types. Recent DNA data (i.e. rbcL nucleotide
sequences) reinforce these two phenotypic characters,
placing Arecaeae as sister to Commelinanae (Chase et al.,
1995). The position of Arecaeae as sister to Commelinanae
may be problematic. Stevenson & Loconte (1995) placed palms
between Juncales and Poales (see Fig. 1-2), while Chase et
al. (1995) put the group as sister to all other Commelinoid
taxa (see Fig. 1-3). The latter placement is supported by
the lack of starch in the endosperm of palm seeds.
Although Arecaceae are clearly monophyletic, more work
is necessary to determine infrafamilial phylogenetic
relationships, and some currently recognized tribes and
subtribes may not be monophyletic. From a cladistic
analysis of morphological and chloroplast DNA restriction
site characters, Uhl et al. (1995) hypothesized that two of
the six subfamilies of Palmae do not constitute clades:
Ceroxyloideae and Arecoideae are polyphyletic and
paraphyletic, respectively (Uhl et al., 1995). The same
analysis supports the monophyly of the tribes of
Ceroxyloideae. The tribes of Arecoideae, however, are not
all monophyletic. Areceae is clearly paraphyletic (Uhl et
al., 1995). Nypoideae with only one species, was used to
root the tree.
Anatomical studies have been used in plant phylogenetic
studies because they are often taxonomically conservative,
Figure 1-2. Cladogram showing Monocot relationships; based
zn morphological characters. Note placement of Arecaceae.
Stevenson & Loconte, 1995)
- Bromeliaceae .Bromeliflorae.
S -" Butomaceae
-.. __ I-cAlismataceae
i -- Scheuchzeriaceae
<*- Alismatidae ,- Hydrocharitaceae
-4- Convmmida Zosteraceae
__ Sparganiaceae Typhes
--- Eriocaulaceae Commehnales
--_ --- Cyperaceae
Figure 1-3. Cladogram showing monocot relationships; based
on taxa common :o both morphological and molecular
analyses. Numbers above line equal branch support. Numbers
below equal bremmer support. Note placement of Arecaceae
(Chase et al. 1995).
and because their use allows an increase in the number of
potentially phylogenetically informative features. In this
study I used foliar anatomical characters because the leaf
is the most obvious and striking organ of the palm, and such
characters had not previously been employed in phylogenetic
studies of this group. Foliar characters for the palms are
abundant and easy to access. Tomlinson (1961) studied the
palms intensively and suggested morphological and anatomical
characters that are shared by certain genera and tribes.
Morphological features and anatomical characters were used
for the current classification of the subfamilies and tribes
of the palms, but these were not assessed from a cladistic
standpoint (Uhl and Dransfield, 1987; Dransfield and Uhl,
1998). Uhl et al. (1995) used several morphological
characters in their phylogenetic analysis (along with DNA
characters), but they did not use many anatomical features.
Tomlinson (1961) considered many of the anatomical and
morphological characters used in his study to be
taxonomically valuable. My analysis will show the taxonomic
value of Tomlinson's assertions.
Foliar Epicuticular Waxes
Foliar epicuticular wax is the outermost layer of wax
present on the leaf surface. This wax accumulates in
response to light, continually over time, and therefore, the
older a leaf, the more wax it may contain (Martin & Juniper,
1970; Taylor, 1995). This continual production of wax is
in response to environmental factors such as wind and rain
that may remove some of the previously deposited wax (Martin
& Juniper, 1970). Wax is synthesized by epidermal cells and
exits to the surface as droplets through pores in the cell
wall (Taiz & Zeiger, 1998). Although the production of wax
is under genetic control, the environment plays a major role
in the thickness, configuration, and distribution of the
waxes (Baker, 1974; Martin & Juniper, 1970). Studies with
Arabidopsis do show correlations between epicuticular wax
structures and chemical composition (Rashotte et al.,
1998). Correlations have been found between chemical
composition and epicuticular wax structure (Baker, 1982;
Preece & Dickinson, 1971).
Certain plants and plant groups have definite foliar
epicuticular wax patterns (Benhke & Barthlott 1983; Hallam &
Chambers, 1970; Whitecross & Armstrong, 1972). Most of the
work showing taxonomic significance of these epicuticular
wax patterns and structures has been done on dicots, while
much of the work on monocots deals with epicuticular wax
structure and chemical composition (Barthlott and Theisen,
1995; Weiller et al, 1994; Denton, 1994; Machado and Barros,
The epicuticular wax layer protects the plant by
providing a barrier against water loss, various air-borne
chemicals, and invasion by pathogens (Juniper & Jeffree,
1983). Epicuticular waxes repel water thereby possibly
slowing germination of fungal spores because moisture is
necessary for the growth of most fungi (Taiz & Zeiger,
1998). It has been shown that the more dense the
epicuticular wax layer, the more water repellent the surface
(Neinhuis & Barthlott, 1997). Certain epicuticular waxes
may deter foraging activity of certain insects (Salatino et
As noted by Barthlott et al. (1998), De Bary first
classified waxes into four categories layers or crusts,
granules, rodlets, and heaped coverings. Since that time
epicuticular waxes have been further categorized and used as
taxonomic tools. Benhke & Barthlott (1983) found that
certain families of Angiosperms have particular epicuticular
wax patterns; some of these are taxonomically significant.
After carefully studying over 13,000 plant specimens,
Barthlott & Frolich (1983) classified four major types of
waxes, the Convallaria-type, Streliztia-type, Berberis-type,
and Aristolochia-type. The Convallaria-type and the
Streliztia-type are restricted to the monocots. They do
not, however, occur in the same families (Barthlott and
Theisen, 1998). The Convallaria-type (parallel oriented
platelets) is characteristic of Liliales, Asparagales, and
Burmanniales. The Strelitzia-type (longitudinally
aggregated rodlets) is characteristic of Arecaceae,
Commelinanae (including Zingiberales, Bromeliales, and
Velloziales) (Barthlott and Frolich, 1983). The
Aristolochia-type of epicuticular wax (transversely ridged
rodlets) is characteristic of ancestral woody angiosperms,
and the Berberis-type (tubular crystals) is characteristic
of ranunculid families and gymnosperms (Hennig et al.,
1994). Barthlott et al. (1998) developed the most recent
and most detailed classification of epicuticular wax
structures and patterns. In his 1998 paper he expanded the
categories and suggested that these characters are
taxonomically significant. Much of his terminology is used
for the epicuticular wax characters in this cladistic study.
Of the four wax types, the Strelitzia-type is found in
palms. Chemical analysis of Strelitzia-type rodlets shows
they consist exclusively of aliphatic wax lipids, mainly
esters (Meusel et al., 1994). Other wax patterns are found
in palms as well as other chemical compositions (Garcia et
al.). Although it previously has been shown that
epicuticular wax structures and patterns are useful
taxonomically, they should, of course, not be used alone to
assess phylogenetic relationships. Meusel et al. (1994)
have shown that Benicasa hispida, a eudicot (Cucurbitaceae),
has rodlets very similar to those found in many monocots.
The chemical composition of the wax rodlets in Benicasa are
triterpenol acetates and triterpenols. This similarity
suggests that convergent evolution may be a problem in
higher-level analyses employing only epicuticular wax
structures and/or patterns, because the waxes of differing
chemical composition may have similar structures and/or
pattern. As with all phylogenetic analyses, to produce more
reliable cladistic hypotheses, wax characters should be used
along with other morphological and anatomical characters.
Since infrafamilial relationships are still rather
problematic in the Arecaceae (Uhl et al., 1995), this
project surveys the palms using foliar epicuticular waxes,
anatomical characters, and morphological features, with an
emphasis on genera within the Coryphoid clade (i.e.,
Coryphoideae). Variation in these characters is used in
cladistic analyses to assess phylogenetic relationships
within the family (and especially within Coryphoideae) as
well as character trends. Traditionally, morphological and
anatomical characters were used in phylogenetic analyses
because they were the only structures available for study.
We now have access to other features, such as epicuticular
waxes or molecular (i.e., DNA) data. It has been shown that
the most resolved cladograms are formed in analyses that
combine all available data (Soltis et al., 1998). These
relationships within the Coryphoid clade (and within palms)
will be re-assessed using my anatomical, micromorphological
and morphological characters, both alone, and in combination
with the features used by Uhl et al. (1995). Finally, the
pattern of variation of epicuticular wax characters on the
combined data trees should be instructive with respect to
the phylogeny of palms.
MORPHOLOGICAL AND ANATOMICAL STUDY
Tomlinrison (1961) conducted an extensive study of palm
anatomy and determined numerous potentially useful taxonomic
characters. Additional characters were highlighted in a
broader study on palms that included morphology and economic
usage (Tomlinson, 1990). However, in neither publication
were characters used in phylogenetic analyses. Some
characters suggested to be of taxonomic significance by
Tomlinson (1961, 1990) are listed in Table 2-1.
A complete list of species used in this study is
provided in Table 2-2. Anatomical samples and voucher
specimens were taken from cultivated plants at the Fairchild
Tropical Garden in Miami, Florida. Fifteen centimeter
segments were cut from the middle half of one side of a
mature leaf. Several 1cm squares were then cut out of the
segments and placed in a 70% alcohol solution. Anatomical
characters were investigated by free-hand sectioning with a
single-edged razor-blade of this preserved material. Thin
sections were stained with phloroglucinol and observed under
Table 2-1. Diagnostic characters and their respective genera
from Tomlinson (1961, 1990):
1. Isolateral Symmetry of the lamina: Bismarkia,
Copernicia Borrassus, Hyphaene, Latania, Medemia,
Nannorrhops, Phoenix, Sabal, Serenoa, Trithrinax.
2. Multicellular hairs with an elliptical base of usually
many sclerotic cells and a distal expanse of thin-
walled cells: Borassus, Hyphaene, Medemia, Pritchardia,
Rhapidophyllum, Lodoicea, Trachycarpus, Chamaerops.
3. Basal cylinder of sclerotic cells surrounding 1 or more
thin walled cells: Arenga, Caryota, Wallichia.
4. Epidermis with long and short cells: Licuala,
5. Adaxial epidermal cells with distinctly sinuous walls
in surface view: Lacosperma, Borassodendron.
6. Stomata surrounded by sclerotic, pitted epidermal
7. Guard cells of stomata sunken: Borassus, Hyphaene,
8. Guard cells with transverse striations on the ledges:
9. Guard cells with only one cuticular ledge:
Table 2-1 continued.
10. Guard cells with several cuticular ledges: Nypa.
11. Adaxial hypodermis with two or more layers, usually 1
abaxial hypodermis: Jubaea, Lodoicea.
12. Adaxial and abaxial hypodermis with two or more layers:
Hyphaene, Nypa, Nannorrhops, Borassus, Latania,
13. Hypodermis wholly fibrous: Pseudophoenix.
14. Substomatal hypodermis cells lobed with subdividing
chamber: Borassodendron, Latania, Phoenix, Borassus.
15. Nonvascular fibers mostly in strands continuous with
and usually indistinguishable from fibrous buttresses
of veins: Borassus, Butia, Hyphaene, Jubaea, Latania,
17. Veins in abaxial mesophyll mostly in contact with
abaxial surface layers: Ceroxylon.
18. Veins in adaxial mesophyll mostly in contact with
adaxial surface layers: Borassodendron, Corypha,
19. Veins almost all attached to one or both surfaces by
fibrous buttresses: Bismarckia, Borassus, Butia,
Hyphaene, Jubaea, Latania, Medemia, Nannorrhops, Sabal.
20. Midrib region not prominent, no vascular bundle:
Table 2-1 continued.
21. Midrib region prominent including many independent
vascular bundles and a single wide band of expansion
cells: Hyphaene, Latania, Lodoicea, Bismarckia,
Borassodendron, Medemia, Borassus, Corypha, Livistona,
Washingtonia, Trachycarpus, Licuala, Acoelorraphe,
Zombia, Brahea, Pholidocarpus, Serenoa, Rhapis, Sabal,
Cryosophila, Johannesteijsmannia, Pritchardia,
Rhapidophyllum, Copernicia, Trithrinax, Coccothrinax,
Chamaerops, Nannorrhops, Thrinax.
Table 2-2. Genera and Species of palms surveyed (arranged
according to the classification of Uhl & Dransfield, 1995).
FTG Ascession number (or collector and collector's number)
follow each species. All specimens vouchered at Fairchild
Tropical Garden unless otherwise noted.
Coccothrinax miraguama (Kunth)Becc., 5861F
Rhapis excelsa Henry ex Rehder, 943043
Chamnaerops humilis Linn., RM157A
Thrinax morissii H. Wendl., 4725
Rhapidophyllum hystrix H. Wendl. & Drude,
Copernicia prunifera (Mill.) H. E. Moore
Acoelorraphe wrightii H. Wendl. ex Becc.,
Livistona chinensis R. Br., 4254
Serenoa repens (Bartram) Small, (Taylor 1
Licuala grandis H. Wendl., 79536A
Nannorrhops ritchiana H. Wendl., 60756A
Kerriodoxa elegans J. Dransf., 84213B
Table 2-2 continued.
Sabal palmetto (Walter) Lodd. ex Schult. &
Schult. f., (Taylor 26 UF herbarium)
Phoenix acaulis Buch-Ham. ex Roxb, 86524A
Latania loddigesii Mart., 72519
Lodoicea maldivica Pers. ex Wendl., 961379B
Hyph a eni nae
Hyphaene petersiana Klolzsch ex Mart., 57129
Calamus concinnus Mart., 71375
Pseudophoenix sargentii H. Wendl., 58872
Ravenea hildebrandti H. Wendl. ex Bouche,
Table 2-2 continued.
Arenga microcarpa Becc., 60741A
Socratea exorrhiza H. Wendl., 93133C
Dypsis cabadae (H. E. Moore) Beentje & J.
Chambeyronia macrocarpa Vieill., 77147
Drymophloeus oliviformis Scheff., 5453A
Pinanga curranii Becc., 92161K
Dictyosperma album H. Wendl. & Drude, 88373A
Allagoptera arenaria Kunth, 714420
Bactris gasipaes Kunth, 66342A
Table 2-2 continued.
Calyptronoma occidentalis (Sw.) H.E. Moore,
Nypa fruticans Wurmb, (On grounds of
Montgomery Botanical Center)
a compound microscope. Drawings of thin-sections were made
using a Bausch and Lomb projector scope.
A portion of each segment was cleared to show venation
patterns. The procedure for leaf clearings was modified
from Zona's (1990) study of the genus Sabal. Tissue
segments were soaked in 2.5% NAOH solution for 24 hours.
These samples were then washed in a 33% commercial bleach
solution for ten minutes. The samples were then washed with
water for ten minutes to remove the bleach, and stained with
a 50% safranin solution.
Morphological characters were observed in the field (at
Fairchild Tropical Garden) or in herbarium specimens (at FTG
or FLAS), supplemented from information taken from the
literature (especially Uhl et al., 1995).
The anatomical and morphological characters used for
this study are characters 1-28 and 38-43 listed in Table 2-
3. These characters are based on those of Tomlinson (1961,
1990) but are modified based on my own observations of the
pattern of variation observed in studied taxa. Characters
showing extensive infrataxon variation were not used. In
addition, certain characters were excluded because they were
invariant, or characterized only a single taxon. Some
features showed continuous variation, e.g., lignified xylem
Table 2-3. Potentially phylogenetically informative
anatomical, vegetative morphological, and
micromorphological characters observed in this study.
Ancestral state (0), derived state (1); based on Nypa
as an outgroup.
1. Plication is reduplicate (0); induplicate (1).
2. Leaves pinnate (0); palmate (1); costapalmate (2).
3. Dichotomous branching present (0); absent (1).
4. Petiole split at base (0); not split (1).
5. Hastula absent (0); present (1).
6. Hypodermis present (0); absent (1).
7. No fibers forming hypodermal layer/s (0); fibers
forming hypodermal layer. (If no hypodermis is present
code as "?" )
8. Hypodermis other than one layer adaxially and
Abaxially (1); hypodermis of one adaxial layer and one
abaxial layer. (Code "?" if missing.)
9. Hypodermis of 2 or more layers adaxially (0);
hypodermis of only 1 layer adaxially(1). (Code "?" if
10. Hypodermis of 2 or more layers abaxially (0);
hypodermis of only 1 layer abaxially (1). (Code "?" if
11. Hairs present (0); hairs absent(l).
12. Dorsoventral lamina (0); isolateral lamina (1).
13. Distinct palisade mesophyll present (0); distinct
palisade absent (1).
Table 2-3 continued.
14. Adaxial and abaxial palisade layer present (0);
adaxial and abaxial palisade absent or only adaxial
layer present (1).
15. Nonvascular fibers not protruding (0); Fibers
16. Nonvascular Fiber bundles (of three or more cells) in
Mesophyll (0); No fiber bundles in mesophyll(1).
17. Solitary nonvascular fibers absent (0);
Solitary nonvascular fibers present (1).
18. Nonvascular fiber bundles lacking on leaf surfaces(0);
attached to abaxial hypodermis or epidermis (1);
attached to adaxial hypodermis or epidermis (2);
bundles attached to both surfaces (3).
19. Nonvascular fiber bundles more prominent near abaxial
surface than near adaxial surface (0); bundles more
prominent near adaxial surface than near abaxial
surface (1); bundles the same on both surfaces (2).
(Code as "?" if not present.)
20. Large and small fiber bundles on the same surface (0);
Uniform fiber bundles on the same
Surface (1). (Code as "?" if not present.)
21. Veins not protruding (0); Veins protruding (1).
22. Large veins attached to both surfaces (0); all veins
independent of surface layer (1); small veins
independent of surface layers and/or small veins
Table 2-3 continued.
independent of surface layers and large
veins attached to abaxial surface (2); small veins
independent of surface layers and large veins attached
to adaxial surface (3); small veins attached to abaxial
surface only and large veins attached to both surfaces
(4); small veins attached to adaxial surface only and
large veins attached to both surfaces (5); all veins
attached to one or both surfaces by well developed
bundles sheath extensions (6); all veins attached to
adaxial surface (7).
23. Large and small vascular bundles outside midrib
present (0); uniform vascular bundles outside midrib
24. Expansion tissue on either side of midvein (0); above
25. Expansion tissue conspicuous (three or more large
expansion cells prominent) (0); inconspicuous(l).
26. Vascular bundle in midrib present (0); absent (1).
27. Midrib not prominent with two or more independent
vascular bundles (0); midrib prominent with two or
more independent vascular bundles (1).
28. Midrib prominent with vascular bundles enclosed in a
common layer of fibers (0); each vascular bundle
enclosed by its own sheath of fibers (1).
Table 2-3 continued.
29. Coalesced epicuticular wax rods not present (0);
30. Curled coalesced epicuticular rods absent (0); present
(1). (code "?" if no rods present).
31. Smooth epicuticular wax absent (0); present (1).
32. Epicuticular wax crystalloids covering entire surface
(0); epicuticular wax crystalloids lacking (1);
Epicuticular wax crystalloids scattered (2).
33. Crust layers of epicuticular wax absent (0);
Crust/layers of epicuticular wax present (1).
34. Platelets absent (0); Platelets present (1).
35. Fissured layers absent (0); present (1).
36. Granules present (0); absent (1).
37. Membranous platelets absent (0); present (1).
38. Branching transverse veins absent (0); such veins
39. Transverse veins present small (0); transverse veins
present large (1).
40. Looping transverse veins present (0); absent(l).
41. Long transverse veins (i.e. veins that cross 3 major
longitudinal veins) absent (0); long transverse veins
42. "v" or "A" shaped lamina(0); "T" shaped lamina (1).
43. Adaxial stomata on segment absent (0); adaxial stomata
on segment absent (1).
walls, lignified vascular and nonvascular fiber bundles, and
were thus difficult to delimit into discrete states; these
characters were also excluded from analysis.
The polarity of the morphological/anatomical character
states used in the study were determined by reference to
Nypa, which is supported as an appropriate outgroup based on
the higher-level phylogenetic analyses of Uhl et al. (1995).
All multistate characters were considered unordered.
Particular characters are discussed in more detail below.
Morphological characters. Vegetative morphological
characters include induplicate or reduplicate plications;
palmate, costapalmate, or pinnate leaves; dichotomous
branching of the stem; condition of the petiole base; and
the presence or absence of a hastula.
Hypodermis. Characters 6-10 involve the presence, type,
position, and number of hypodermal layers. Figure 2-1 is an
example of a fibrous hypodermal layer as represented in
Epidermal hairs and stomata. The presence or absence of
hairs on the epidermis, and stomata on the adaxial surface
of the epidermis are used as characters.
Palisade mesophyll. Characters 13 and 14 deal with the
presence and placement of the palisade mesophyll. An
example of a distinct palisade layer is given in Figure 2-1.
Figure 2-1. Cross-section of Pseudophoenix sargentii. (A)
Cross section of midvein showing common sclerotic fibers
(sf) enclosing one vascular bundle (vb) and expansion
tissue (et) on either side of midvein. (B) Enlargement of
leaf segment cross-section showing fibers (f), fibrous
hypodermal layer (fh), palisade mesophyll (pm), vascular
bundles (vb) and protruding fibers (pf).
Figure 2-2. Diagram of cross-section of leaf segment of
Kerriodoxa elegans. Note vascular bundles surrounded by
fibers, solitary fibers (fc) in mesophyll, one-layered
-- """-" h
^)~ f e/_"----gP
Fibers. Characters 15-20 involve the presence of fibers in
bundles (three or more fiber cells in a bundle) and the
position of the fiber bundles. Figure 2-1 shows nonvascular
fiber bundles protruding from the abaxial surface. Figure
2-2 shows solitary fibers (three or fewer fibers cells in
Veins. Characters 21-23 are derived from the position of
veins in the mesophyll. Some veins are pectinate, see
Figure 2-3. Veins may be attached to the adaxial and/or
abaxial surface, some laminas have large and small vascular
bundles, and some others have fibrous buttresses, i.e.,
fibrous extensions attached to the vascular bundle (see Fig.
Expansion tissue. The expansion tissue is located in the
midrib region. It is believed to play a role in leaf
folding. Characters 24 and 25 deal with the position of
expansion tissue in the midrib (see Fig. 2-5).
Vascular bundles in midrib. Characters 27 and 28 deal with
differences in the midrib (see Figs. 2-6 and 2-7). The
midrib of Livistona is characterized as one with independent
vascular bundles, because the fibrous layer does not
surround all bundles.
Pattern of transverse veins. Variation in the pattern of
commissural veins with respect to longitudinal veins
Figure 2-3. Diagram of cross-section of leaf segment of
Bactris gasipaes. Note vascular bundles (vb), fiber
bundles (f), protruding vascular bundles (pvb).
Figure 2-4. Diagram of cross-sections leaf segments of
Hyphaene petersiana. (A) Lamina section. Note bundle sheath
extensions (b) attached to vascular bundles (vb) and
hypodermis (h) on either side of mesophyll. (B) Cross
section of midvein showing two independent vascular bundles
(vb) each surrounded by own sclerotic fibers (f). The
expansion tissue (et) is above the midvein.
Figure 2-5. Diagram of cross-sections of leaf segments of
midveins. (A) Midvein with independent vascular bundles of
Nannorhops ritchiana. Note vascular bundles (vb) and fibers
(f). The expansion tissue )et) is above the midvein. (B)
Note xylem vessels (x) in common sclerotic shield of fibers
(sf) in Bactris gasipaes. The expansion tissue (et) is one
either side of the midvein.
Figure 2-6. Diagram of cross-section of leaf segment of
Livistona chinensis showing many independent vascular
bundles (vb) in midvein. Note position of fibers (f) and
expansion tissue (et).
Figure 2-7. Diagram of large and branching transverse
veins in leaf segment of Lodoicea maldivica (10x).
provides useful characters (see Figs. 2-8 to 2-10). Certain
similar patterns have been observed in Sabal (Zona, 1990).
Segment shapes in the lamina. Figures 2-11 and 2-12
represent lamina shapes. Some leaves have upright "v" and
or inverted "A shaped lamina segments, while some have
more "T" shaped lamina segments.
Figure 2-8. Diagram of long and looping transverse veins
in leaf segment of Nypa fruticans (0lx).
Figure 2-9. Diagram of long and short transverse veins in
leaf segment of Thrinax morrissii (10x).
Figure 2-10. Diagram of vein patterns in leaf segment of
Kerriodoxa elegans. Note large branching transverse veins
Figure 2-11. Diagram of cross-section of leaf segment of
Licuala grandis. Note "V" shaped leaf section, expansion
tissue (et), and vascular bundle (vb).
Figure 2-12. Diagram of cross section of leaf segment of
Socratea exhorriza. Note "T"shaped leaf blade and xylem
vessels :x) enclosed in common layer of sclerotic fibers
EPICUTICULAR WAX STUDY
The epicuticular wax characters used in this study were
compared to those used in Barthlott et al. (1998) in which
epicuticular waxes are characterized as films,
layers/crusts, and crystalloids.
Films are very thin. They represent the final layer of
the cuticle barely visible with the Scanning Electron
Microscope (SEM) (Barthlott et al., 1998). Layers and
crusts represent thick continuous coverings. Barthlott and
colleagues further described three different types of layers
and crusts-- smooth layers, crusts, and fissured layers.
Smooth layers are thin and have no prominent sculpturing.
They are distinguishable from films in SEM because they show
cracking. Crusts are continuous coverings with prominent
sculpturing. Often these crusts are very thick. Fissured
layers are usually thick, crusty coverings, fractured by
naturally occurring cracks (Barthlott et al., 1998).
Crystalloids represent distinct individual wax
projections. Barthlott et al. (1998) described five
categories of crystalloids: granules, plates and platelets,
rodlets, threads, and tubules. Granules are mostly
isodiametric, and often rounded crystalloids. Plates and
platelets represent flat crystalloids that project upward
differing in shape and size. Rodlets are massive structures
with a distinct longitudinal axis. Barthlott and associates
described four types of rodlets, which differ in diameter
and orientation. Threads are fine, long, crystalloids that
often form a felt-like covering. Tubules are hollow
crystalloids, with a terminal opening. Several types are
known, differing from each other in branch angle. Various
orientations and aggregations of these waxes are also
discussed in Barthlott et al. (1998).
The Streliztia-type of epicuticular wax is an
aggregation of rods. As noted by Barthlott (1983) and
discussed later, the form of these rods can vary in the
Streliztia-type wax, some being curled and others straight.
Others of the coalesced rods may form crusts or layers.
Some may form upright fences.
Barthlott and colleagues (1998) also discussed the
possibility that some leaf surfaces contain more that one
epicuticular wax type. Thus providing a firm foundation for
the classification of epicuticular wax structures. However,
the Barthlott classification, or any general-purpose
classification, necessarily requires modification, when
applied to a particular plant group, as discussed below.
Many of the genera assessed in the phylogenetic
analysis of Arecaceae by Uhl et al. (1995) were collected,
observed and used in this investigation. The epicuticular
wax samples were taken from plants cultivated at the
Fairchild Tropical Garden in Miami, Florida. A 15 cm leaf
segment was cut from healthy leaves, flattened, and air
dried. Immature leaves were not used because they may not
have developed the mature form of epicuticular wax
structures and patterns. For consistency only the adaxial
surface was viewed using the SEM. Each specimen was
labeled, including the name, date, location, and the
Fairchild Tropical Garden accession number. Voucher
specimens were made of those plants not already vouchered
and deposited in the herbarium of Fairchild Tropical Garden.
Because the exact chemical composition of the epicuticular
wax of each leaf was not known, leaves were air-dried. It
was thought that excessive heat might damage the
epicuticular wax structures (Reed, 1982). Other available
methods included critical point drying and the use of
hexamethyldisilizane (HMDA) (Dykstra, 1993). With both of
these methods it is important to keep the specimen as cool
as possible (Reed, 1982). Critical point drying involves a
pressurized chamber filled with cold carbon dioxide. This
process may obscure the wax structures since the alcohol and
organic solvents used may interfere with the epicuticular
wax structures. HMDA is often considered to be the
simplest method for preparation of material for the SEM; it
allows the quick use of fresh material. However, here again
the organic solvents may dissolve or alter epicuticular wax
structures. Hence, air drying is considered to be the best
method for this investigation.
After specimens were air dried, one centimeter segments
were placed adaxiall side up) onto studs, gold coated using
the Eiko IB4 sputter coaster, and placed into the Hitachi
4000 Field Emission Scanning Electron Microscope. The
scope's water chiller chilled the diffusion chamber to
minimize heating that could possibly damage the specimen.
The accelerating voltage of the scope was 6.00 kv.
Epicuticular Wax Characters
The epicuticular wax characters used in this study are
character 29-37 listed in Table 2-3. These characters
differ somewhat from those described by Barthlott et al.
(1998). Although the Barthlott system was taken into
consideration, it was necessary to modify the categories of
Barthlott et al., based on the patterns of variation in
epicuticular waxes observed in this study.
Many of the epicuticular wax characters listed on Table
2-3 can occur on the same leaf surface. They vary
independently, with the exception of fissuredd layers" (a
type of layered epicuticular wax) and curled coalesced rods
(a type of coalesced rods). All characters are treated as
unordered. Character states are qualitatively different,
and are coded as presence/absence features. Polarity is
inferred based on rooting the cladograms resulting from the
cladistic analysis with Nypa. Nypa was hypothesized to be
the sister group of all other palms by Uhl et al. (1995),
and therefore, is suitable outgroup for this study. The
nine epicuticular wax characters used in this study are
described below (see also Table 2-3).
Epicuticular wax crystalloids. There are five different
kinds of epicuticular wax crystalloid structures:
platelets, granules, membranous platelets, coalesced rods,
and curled coalesced rods.
Smooth epicuticular wax layer. This layer represents a
surface that is relatively smooth though may show some
artificial cracking and or rough surfaces. No crystalloids
project from it. This smooth surface differs from that
described by Barthlott et al. (1998) in that films and
smooth layers are distinguished in their study. Barthlott
et al. (1998) separated them based on thickness and degree
of smoothness, but I found this distinction difficult to
make. Examples of smooth surfaces are given in Figures 3-1
A and B. Crusts/layers of epicuticular wax. This wax type
Figure 3-1. A) Socratea exorhiza, note smooth epicutiular
wax layer. B) Licuala grandis, note smooth epicuticular wax
represents a covering that is typically thick and
continuous. There are two types of crusts/layers, i.e.,
fissured layers and crusts that differ in surface
sculpturing. Examples of crust/layers are shown in Figures
3-2 B & 3-3 A and B. Figure 3-2 B represents crusts of
coalesced epicuticular wax rods. Figure 3-3 A and B
represent fissured layers of epicuticular wax. Fissured
layers are formed when thick continuous smooth coverings
break and separate into flat sheets (Fig. 3-3 A and B).
Coalesced epicuticular wax rods. Coalesced rods represent
rods that have fused together. This fusion of rods often
results in the formation of thick crusts. Often massive
amounts of wax are present. Sometimes the fused rods form
upright barriers as in Figure 3-4. Barthlott et al. (1998)
use the term rodlets for this type of wax and described four
different sub-types. Subdivisions of this category were not
distinguished in this study, with the exception of curled,
coalesced rods (Fig. 3-2 B). These rods are fused and
curled in contrast to straight, upright fused rods. Curled
rods may also be scattered over the cuticular surface (see
Fig. 3-2 A).
Granules. These crystalloids are rounded structures that
project from the cuticular surface. They are typically
scattered (Fig. 3-5 A and B). Barthlott et al. (1998)
Figure 3-2. (A) Phoenix acaulis, note scattered curled
coalesced epicuticular wax rods. (B)Copernicia prunifera,
note coalesced epicuticular wax rods.
Figure 3-3. (A) Allagoptera arenaria, note fissured
layers. (B) Acoelorraphe wrightii, fissured layers.
Figure 3-4. (A) Latania loddigesii, note coalesced
epicuticular wax rods sometimes forming an upright structure
around stomata. (B) Nannorrhops ritchiana. Note coalesced
rods coalesced sometimes forming upright barriers.
Figure 3-5. (A) Rhapis excelsa, note granules (g) and
platelets (p). (B) Lodoicea maldivica note granules.
suggest that this crystalloid type is often mistaken as an
Platelets. Platelets are flat crystalloids that project
from the cuticular surface. Barthlott et al. (1998)
described several different kinds of plates and platelets on
the basis of size, shape and orientation. The variation
observed in this study did not coincide with these
delimitations. Thus, all flat structures that
project from the surface here are considered to be platelets
(Fig. 3-6 B).
Membranous platelets. These structures differ from typical
platelets in that they are thinner and appear flimsy.
Barthlott et al. (1998) considered membranous platelets to
be interconnected and to protrude at acute angles. They are
often found together with other kinds of crystalloids (Fig.
Scattered epicuticular wax crystalloids. This pattern often
represents various kinds of crystalloid structures scattered
across a leaf surface (Fig. 3-5 B).
On the basis of my observations of the patterns of
variation within the Arecaceae, using the above delimited
categories of wax types, the characters and character states
listed in Table 2-3 are suggested to be of potential
Figure 3- 6. (A) Calyptronoma occidentalis, note membranous
platelets. (B) Pinanga cunnani, note platelets.
Cladistic Analysis Based on Anatomical and
The taxa used in my analysis of anatomical and
micromorphological data are listed in Table 2-2. Many of
these same taxa were also used by Uhl et al. (1995) in their
cladistic analysis. The various characters and character
states of each taxon are tabulated in the data matrix shown
in Table 4-1 (and characters 1-43 in this matrix represent
anatomical and micromorphological features). A preliminary
heuristic search was done using Hennig86 (Farris, 1989) that
produced trees very similar to those produced by PAUP, as
discussed below. A heuristic search was performed using the
Beta test version of PAUP* 4.Obl for the Macintosh computer
(Swofford, 1997). All multistate characters were unordered
and all characters were equally weighted. Forty of the
forty three characters were phylogenetically informative.
The tree-bisection-reconnection (TBR) branch swapping
algorithm was used on trees generated from 500 random
addition replicates. This search produced eight most
parsimonious trees, with a length of 190, a consistency
index (CI) of 0.29, and a retention index (RI) of 0.56. The
trees were rooted using Nypa as a functional outgroup, as
TABLE 4-1. DATA MATRIX OF 223 CHARACTERS FOR CLADISTIC STUDY.
Characters 1-43 represent anatomical/micromorphological
characters; characters 44-80 represent Uhl et al. (1995)
morphological characters; characters 81-223 represent Uhl et al.
(1995) molecular characters.
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...5 ~ ~- -' 5'. .. .. .. . .. .. . .. .. .
1OO COOC1001 3200601001100001 000001100000001.010110-0011-
11OOOOOO1 0010001011~1010010001101111110000101 01111110111011100111 0111111O0 111010010
0010011 01111100010010111111110101 01001 0101111110101110 0100111 000 1000111011 11011
10011111CC1100 0000 1000 100 00111010 110 111
"~7? >733?37"777777'733~75'7'?33 ;?? 7?573777'77333?333?3??
.. ..... ... ... . .. .. .5 ? .. . ... .. ... ...'. .... ..... ..
OC.1001000 .1.1 301 00110 0011 0110C 0000 00010001 10-0010-
-11.CO0001100010 001 010 1>0100011011111 01010001101 01110100010 1011110>10011100110
??oc??o 9ooo????? ????????? ?? ?????????????????????????? ???????????????????? ??????????????
7 0.07??7????7?73?7 7177??3 3?70?? ?33?37777>73?.7.??7?>77777?37777
00-110000. 1 ". 010 31 00000 1 10001C01020??100111?2?01000-
IO^? O?? 000?????????????????????????????? ???????????????????????????????????????????????
???3';7??"?*?7 '"?? ?7'3?7?">*?7?????3?375"73"5???? 77?3??3'1"????????????7? 3??3??>7:?357'?
.... ... .00 0... . .
0001 -1- 110 010 11 0 1 10 01 4100111421?010011OO1 10??0771??01?????????
2. 5. .5 .. 55 5 -5 5'5 5 55 5 '. -- -5 5
11101001110001010C10040100000 1 0191100900000000000000010000-0020-0-
300000011000100011101101011Ooc111110001000010011010001111100010111110101 0 1001101110
Chta' zcp& humilis
TABLE 4-1 continued.
???????? ,7?? ????????'?????????????????????????????????7?????.
10110110ooo iiooiooiooo iioiooiiiiioooioioilllllOl011110100101011 110001iiii0 oli ooiocoo01111
11020011001 001110100100011011111111000101011101101110101001010 11111001111110110
000001101111111 C00010101111110111011100011011111110001110100110M111000100001111 111011011
? n'">?? ????????????????????????????????????????????????????????????'???????? ???';';'''7""7
????????????? ?????7">""7S7>7'77'>'55'7 7 77p7p???? ?????7777??? ??????????????????
suggested in the analysis of Uhl et al. (1995). The strict
consensus tree (Fig. 4-1) shows a clade containing
Nannorrhops + Hyphaene + Latania + Lodoicea + Sabal + Rhapis
+ Phoenix + Copernicia; Coccothrinax + Kerriodoxa + Licuala;
Dictyosperma + Pseudophoenix + Allagoptera; Socratea +
Calamus + Ravenea + Arenga; and Drymophloeus + Dypsis +
Calyptronoma. In addition, the Coryphoideae form a clade,
with Thrinax sister to all other members of the Coryphoid
clade included in the analysis. As in a representative tree
(Fig. 4-2) the Nannorrhops + Hyphaene + Latania + Lodoicea +
Sabal + Rhapis + Phoenix + Copernicia clade share the
following characteristics: prominent midribs with two or
more vascular bundles (character # 27), midrib vascular
bundles enclosed in a common layer of fibers (character
#28), and large transverse veins (character #39). The
members of Coccothrinax + Kerriodoxa + Licuala clade are
united by the lack of epicuticular wax crystalloids
(character #32). In some trees Livistona + Serenoa +
Acoelerraphe + Chamaerops form a clade based on character
#27 (midrib with two or more vascular bundles).
Rhapidophyllum is sister to this clade. The Coryphoideae
share the following derived characters: induplicate
plication (character #1), palmate leaves (character #2),
presence of a hastula (character #5), and fiber bundles near
the adaxial surface (character #19). Dictyosperma,
Figure 4-1. Strict consensus of eight most parsimonious
trees resulting from analysis of anatomical and
micromorphological data (characters 1-43). Full names of
each taxon are in Table 4-1. Decay values given above the
Pseudophoenix, and Allagoptera all have a one layered
hypodermis (character #9) and adaxial bundles attached to
the surface (character #18). The monophyly of the group
containing Drymophloeus, Dypsis, and Calyptronoma is
supported by the inconspicuous expansion tissue (character
#25) and absence of a distinct palisade layer (character
#13), and Socratea, Calamus, Ravenea, and Arenga all have
smooth epicuticular wax (character #31). Almost none of
these clades is strongly supported (see Fig.4-1).
The pattern of character state changes on the most
parsimonious trees resulting from the analysis of anatomical
and micromorphological characters were explored using
MacClade version 3.1 (Maddison & Maddison, 1992).
Noteworthy character states functioning as synapomorphies in
these trees include a prominent midvein with two or more
vascular bundles (character #27), prominent midrib enclosed
in common layer of fibers (character #28), coalesced
epicuticular wax rods (character #29), smooth epicuticular
wax (character #31), scattered epicuticular wax crystalloids
(character #32-2), crystalloids covering the entire surface
(character #32-0), absence of crystalloids (character #32-
1), crusts/layers of epicuticular wax (character #33), and
fissured layers (character #35). Character #27 helps define
two clades; both are in the Coryphoideae (see Fig. 4.3).
Character #28 helps define the same clades but its value is
Figure 4-2. Representative most parsimonious tree from
analysis of anatomical and micromorphological data. Length
190. CI = 0.29, RI = 0.56. The letters represent the
following characters a) 3-1, 14-1, 22-2, 32-2; b) 4-0, 17-
1, 21-1, 22-0; c) 5-0, 20-0, 41-1, 42-1, 43-0; d) 11-0, 40-
1; e) 14-0, 3-0, 39-0, 13-0, f) 16-0; g) 10-0, 29-1; h) 5-
0, 11-0, 12-0, 22-7, 32-2, 36-0, 38-1, 43-0; i) 8-0, 9-0,
19-2; j) 31-1, 32-1, 40-1, 41-1; k) 2-2, 4-0, 22-6; 1) 11-
0, 12-0, 17-1, 18-0, 34-1, 36-0; m) 42-0; n) 22-3, 33-1,
40-1; 0) 27-1, 30-0, 39-1, p) 2-0, 5-0, 19-2, 26-1, 32-2;
q) 11-1, 12-1; r) 8-0, 22-6, 32-2, 34-1, 41-1; s) 4-0, 10-
0, 11-1, 17-1, 38-1, 39-1, 40-1, 42-0; t) 9-0, 16-0; u) 17-
1; v) 32-1; w) 13-1, 33-0, 35-0; x) 2-2, 1-0, 20-1, 22-3;
y) 12-1, 14-0, 29-1, 41-1; z) 16-0, 39-1; aa) 13-1, 21-1,
22-0, 23-1, 24-0; bb) 11-1, 38-1, 42-0; cc) 20-1; dd) 27-1;
ee) 2-2, 16-0, 18-2, 22-0, 41-1, ff) no unambiguous
characters; gg) 13-1, 35-0, 33-0; hh) 22-4, 4-0; ii)l-l,
18-3, 42-1; jj) 18-3, 19-1, 41-1; kk) 4-0, 7-1, 15-1; 11)
10-0, 17-1, 22-8, 42-1; mm) 8-0, 20-1; nn) 9-0, 18-1; 00oo)
16-1, 32-0; pp) 25-1; qq) 4-0, 39-1; rr) 5-1, 21-1; ss) 1-
1, 41-1; tt)5-1, 21-1; uu)17-1; vv) 31-1; ww) 1-0, 10-0,
41-1; xx) 32-1; yy) no unambiguous characters; zz)36-0 ; A)
4-0, 16-1, 17-1, 37-1, 42-1; B) 13-1, 25-1; C) 8-1, 9-1,
22-1; D) 21-1, 24-1, 37-1, 42-1; E) 6-1, 18-2, 34-1; F) 4-
1; G) 3-1, 14-1, 22-2, 32-2, 36-1; H) 33-1, 35-1. Full
names of each taxon are in Table 4-1.
Figure 4-3. Representative most parsimonious tree from
analysis of anatomical and micromorphological data.
Character #27. Midrib not prominent, lacking two or more
vascular bundles as indicated by white lines; midrib
prominent with two or more independent vascular bundles
represented by black lines. Full names of each taxon are in
I '--in UCUALA
o C- RAVENEA