• TABLE OF CONTENTS
HIDE
 Front Cover
 Front Matter
 Table of Contents
 Botanical characteristics
 Chemical and physical characteristics...






Group Title: Bulletin - University of Florida Agricultural Experiment Station ; 503
Title: The genus aleurites in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE PAGE TEXT
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026523/00001
 Material Information
Title: The genus aleurites in Florida
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 40 p. : ill. ; 23 cm.
Language: English
Creator: Dickey, R. D ( Ralph Davis ), 1904-
Gilbert, Seymour G ( Seymour George )
Gropp, Clare M
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1952
 Subjects
Subject: Aleurites   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Includes bibliographies.
Statement of Responsibility: by R.D. Dickey, Seymour G. Gilbert and Clare M. Gropp.
General Note: Cover title.
Funding: This collection includes items related to Florida’s environments, ecosystems, and species. It includes the subcollections of Florida Cooperative Fish and Wildlife Research Unit project documents, the Florida Sea Grant technical series, the Florida Geological Survey series, the Howard T. Odum Center for Wetland technical reports, and other entities devoted to the study and preservation of Florida's natural resources.
 Record Information
Bibliographic ID: UF00026523
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000925786
oclc - 18267325
notis - AEN6442

Table of Contents
    Front Cover
        Page 1
    Front Matter
        Page 2
        Page 3
    Table of Contents
        Page 4
    Botanical characteristics
        Page 5
        Introduction
            Page 5
        Tung tree
            Page 5
            Page 6
            Page 7
            Page 8
            Page 9
            Page 10
        Mu-oil tree
            Page 11
            Page 12
            Page 13
            Page 14
            Page 15
            Page 16
        Japan wood oil tree
            Page 17
            Page 18
            Page 19
            Page 20
            Page 21
        Candlenut trees
            Page 22
            Page 23
            Page 24
            Page 25
        Soft lumbang
            Page 26
            Page 27
            Page 28
        Key to species of aleurites
            Page 29
        Acknowledgment
            Page 30
        Literature Cited
            Page 30
    Chemical and physical characteristics of the oils
        Page 31
        Introduction
            Page 31
            Page 32
        Matrials and methods
            Page 33
            Page 34
        Results
            Page 35
            Page 36
            Page 37
        Discussion
            Page 38
        Summary
            Page 39
        Literature cited
            Page 40
Full Text
CATALOGEI
JAN 2 1953


Bulletin 503


October 1952


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
WILLARD M. FIFIELD, Director
GAINESVILLE, FLORIDA



The Genus Aleurites in Florida:


Part I.


Botanical Characteristics;


Part II. Chemical and Physical
Characteristics of the Oils
By R. D. DICKEY, SEYMOUR G. GILBERT and CLARE M. GROPP



TECHNICAL BULLETIN

Fig. 1.-Tung (Aleurites fordi) orchard near Lamont, Florida.








BOARD OF CONTROL

Frank M. Harris, Chairman, St. Petersburg
Hollis Rinehart, Miami
Eli H. Fink, Jacksonville
George J. White, Sr., Mount Dora
Mrs. Alfred I. duPont, Jacksonville
George W. English, Jr., Ft. Lauderdale
W. Glenn Miller, Monticello
W. F. Powers, Secretary, Tallahassee

EXECUTIVE STAFF
J. Hillis Miller, Ph.D., President
J. Wayne Reitz, Ph.D., Provost for Agr.3
Willard M. Fifield, M.S., Director
J. R. Beckenbach, Ph.D., Asso. Director
L. 0. Gratz, Ph.D., Assistant Director
Rogers L. Bartley, B.S., Admin. Mgr.3
Gee. R. Freeman, B.S., Farm Superintendent


MAIN STATION, GAINESVILLE

AGRICULTURAL ECONOMICS
H. G. Hamilton, Ph.D., Agr. Economist
R. E. L. Greene, Ph.D., Agr. Economist 3
M. A. Brooker, Ph.D., Agr. Economist 3
Zach Savage, M.S.A., Associate
A. H. Spurlock, M.S.A., Associate
D. E. Alleger, M.S., Associate
D. L. Brooke, M.S.A., Associate4
M. R. Godwin, Ph.D., Associate
H. W. Little, M.S., Assistant
W. K. McPherson, M.S., Economist
Eric Thor, M.S., Asso. Agr. Economist
J. L. Tennant, Ph.D., Agr. Economist
Cecil N. Smith, M.A., Asso. Agr. Economist
Levi A. Powell, Sr., M.S.A., Asst. Agr.
Economist

Orlando, Florida (Cooperative USDA)
G. Norman Rose, B.S., Asso. Agri. Economist
J. C. Townsend, Jr., B.S.A., Agricultural
Statistician 2
J. B. Owens, B.S.A., Agr. Statistician 2
J. K. Lankford, B.S., Agr. Statistician

AGRICULTURAL ENGINEERING
Frazier Rogers, M.S.A., Agr. Engineer1 s
J. M. Johnson, B.S.A.E., Agr. Eng.'
J. M. Myers, B.S., Asso. Agr. Engineer
J. S. Norton, M.S., Asst. Agr. Eng.

AGRONOMY
Fred H. Hull, Ph.D., Agronomist 1
G. B. Killinger, Ph.D., Agronomist
H. C. Harris, Ph.D., Agronomist
R. W. Bledsoe, Ph.D., Agronomist
W. A. Carver, Ph.D., Associate
Darrel D. Morey, Ph.D., Associate 2
Fred A. Clark, M.S., Assistant
Myron C. Grennell, B.S.A.E., Assistant 4
E. S. Horner, Ph.D., Assistant
A. T. Wallace, Ph.D., Assistant 3
D. E. McCloud, Ph.D., Assistant 3
H. E. Buckley, B.S.A., Assistant
E. C. Nutter, Ph.D., Asst. Agronomist

ANIMAL HUSBANDRY AND NUTRITION
T. J. Cunha, Ph.D., An. Husb.1
G. K. Davis, Ph.D., Animal Nutritionist 3
S. John Folks, Jr., MS., Asst. An. Husb.
Katherine Boney, B.S., Asst. Chem.
A. M. Pearson, Ph.D., Asso. An. Husb.3
John P. Feaster, Ph.D., Asst. An. Nutri.
H. D. Wallace, Ph.D., Asst. An. Hush. .
M. Koger, Ph.D., An. Husbandman 3
E. F. Johnston, M.S., Asst. An. Husbandman
J. F. Hentges, Jr., Ph.D., Asst. An. Hush.

DAIRY SCIENCE
E. L. Fouts, Ph.D., Dairy Tech.1 3
R. B. Becker, Ph.D., Dairy Husb.3
S. P. Marshall, Ph.D., Asso. Dairy Husb.3
W. A. Krienke, M.S., Asso. Dairy Tech.3


P. T. Dix Arnold, M.S.A., Asst. Dairy Husb."
Leon Mull, Ph.D., Asso. Dairy Tech.
H. H. Wilkowske, Ph.D., Asst. Dairy Tech.
James M. Wing, M.S., Asst. Dairy Husb.

EDITORIAL
J. Francis Cooper, M.S.A., Editors
Clyde Beale, A.B.J., Associate Editor :
L. Odell Griffith, B.A.J., Asst. Editor :
J. N. Joiner, B.S.A., Assistant Editor 3
William G. Mitchell, A.B., Assistant Editor

ENTOMOLOGY
A. N. Tissot, Ph.D., Entomologist
L. C. Kuitert, Ph.D., Associate
H. E. Bratley, M.S.A., Assistant
F. A. Robinson, M.S., Asst. Apiculturist
R. E. Waites, Ph.D., Asst. Entomologist

HOME ECONOMICS
Ouida D. Abbott, Ph.D., Home Econ.'
R. B. French, Ph.D., Biochemist

HORTICULTURE
G. H. Blackmon, M.S.A., Horticulturist1
F. S. Jamison, Ph.D., Horticulturist 3 4
Albert P. Lorz, Ph.D., Horticulturist
R. K. Showalter, M.S., Asso. Hort.
R. A. Dennison, Ph.D., Asso. Hort.
R. H. Sharpe, M.S., Asso. Horticulturist
V. F. Nettles, Ph.D., Asso. Horticulturist
F. S. Lagasse, Ph.D., Asso. Hort.2
R. D. Dickey, M.S.A., Asso. Hort.
L. H. Halsey, M.S.A., Asst. Hort.
C. B. Hall, Ph.D., Asst. Horticulturist
Austin Griffiths, Jr., B.S., Asst. Hort.
S. E. McFadden, Jr., Ph.D., Asst. Hort.
C. H. VanMiddelem, Ph.D., Asst. Biochemist
Buford Thompson, M.S.A., Asst. Hort.
James Montelaro, Ph.D., Asst. Horticulturist

LIBRARY
Ida Keeling Cresap, Librarian
PLANT PATHOLOGY
W. B. Tisdale, Ph.D., Plant Pathologist 1 3
Phares Decker, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist and Botanist
Robert W. Earhart, Ph.D., Plant Path.2
Howard N. Miller, Ph.D., Asso. Plant Path.
Lillian E. Arnold, M.S., Asst. Botanist
C. W. Anderson, Ph.D., Asst. Plant Path.

POULTRY HUSBANDRY
N. R. Mehrhof, M.Agr., Poultry Husb.' a
J. C. Driggers, Ph.D., Asso. Poultry Husb.

SOILS
F. B. Smith, Ph.D., Microbiologist 1
Gaylord M. Volk, Ph.D., Soils Chemist
J. R. Neller, Ph.D., Soils Chemist
Nathan Gammon, Jr., Ph.D., Soils Chemist
Ralph G. Leighty, B.S., Asst. Soil Surveyor
G. D. Thornton, Ph.D., Asso. Microbiologist 7
Charles F. Eno, Ph.D., Asst. Soils Micro-
biologist 4
H. W. Winsor, B.S.A., Assistant Chemist
R. E. Caldwell, M.S.A., Asst. Chemist34
V. W. Carlisle, B.S., Asst. Soil Surveyor
J. H. Walker, M.S.A., Asst. Soil Surveyor
S. N. Edson, M. S., Asst. Soil Surveyor 3
William K. Robertson, Ph.D., Asst. Chemist
0. E. Cruz, B.S.A., Asst. Soil Surveyor
W. G. Blue, Ph.D., Asst. Biochemist
J. G. A. Fiskel, Ph.D., Asst. Biochemist
H. F. Ross, B.S., Soils Microbiologist
L. C. Hammond, Ph.D., Asst. Soil Physicis
H. L. Breland, Ph.D., Asst. Soils Chem.
VETERINARY SCIENCE
D. A. Sanders, D.V.M., Veterinarian '
M. W. Emmel, D.V.M., Veterinarian "
C. F. Simpson, D.V.M., Asso. Veterinarian
L. E. Swanson, D.V.M., Parasitologist
Glenn Van Ness, D.V.M., Asso. Poultry
Pathologist
W. R. Dennis, D.V.M., Asst. Parasitologist








BRANCH STATIONS

NORTH FLORIDA STATION, QUINCY

W. C. Rhoades, Jr., M.S., Entomologist in
Charge
R. R. Kincaid, Ph.D., Plant Pathologist
L. G. Thompson, Jr., Ph.D., Soils Chemist
W. H. Chapman, M.S., Asso. Agronomist
Frank S. Baker, Jr., B.S., Asst. An. Husb.
T. E. Webb, B.S.A., Asst. Agronomist
Frank E. Guthrie, Ph.D., Asst. Entomologist
Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist
Mobile Unit, Marianna
R. W. Lipscomb, M.S., Associate Agronomist
Mobile Unit, Pensacola
R. L. Smith, M.S., Associate Agronomist
Mobile Unit, Chipley
J. B. White, B.S.A., Associate Agronomist

CITRUS STATION, LAKE ALFRED
A. F. Camp, Ph.D., Vice-Director in Charge
W. L. Thompson, B.S., Entomologist
R. F. Suit, Ph.D., Plant Pathologist
E. P. Ducharme, Ph.D., Asso. Plant Path.
C. R. Steams, Jr., B.S.A., Asso. Chemist
J. W. Sites, Ph.D., Horticulturist
H. O. Sterling, B.S., Asst. Horticulturist
H. J. Reitz, Ph.D., Horticulturist
Francine Fisher, M.S., Asst. Plant Path.
I. W. Wander, Ph.D., Soils Chemist
J. W. Kesterson, M.S., Asso. Chemist
R. Hendrickson, B.S., Asst. Chemist
Ivan Stewart, Ph.D., Asst. Biochemist
D. S. Prosser, Jr., B.S., Asst. Horticulturist
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Chemist
Alvin H. Rouse, M.S., Asso. Chemist
H. W. Ford, Ph.D., Asst. Horticulturist
L. C. Knorr, Ph.D., Asso. Histologist4
R. M. Pratt, Ph.D., Asso. Ent.-Pathologist
J. W. Davis, B.S.A., Asst. in Ent.-Path.
W. A. Simanton, Ph.D., Entomologist
E. J. Deazyck, Ph.D., Asso. Horticulturist
C. D. Leonard, Ph.D., Asso. Horticulturist
W. T. Long, M.S., Asst. Horticulturist
M. H. Muma, Ph.D., Asso. Entomologist
F. J. Reynolds, Ph.D., Asso. Hort.
W. F. Spencer, Ph.D., Asst. Chem.
I. H. Holtsberg, B.S.A., Asst. Ento.-Path.
K. G. Townsend, B.S.A., Asst. Ento.-Path.
J. B. Weeks, B.S., Asst. Entomologist
R. B. Johnson, M.S., Asst. Entomologist
W. F. Newhall, Ph.D., Asst. Biochem.
W. F'. Grierson-Jackson, Ph.D., Asst. Chem.
Roger Patrick, Ph.D., Bacteriologist
Marion F. Oberbacher, Ph.D., Asst. Plant
Physiologist
Evert J. Elvin, B.S., Asst. Horticulturist

EVERGLADES STATION, BELLE GLADE
W. T. Forsee, Jr., Ph.D., Chemist Acting in
Charge
R. V. Allison, Ph.D., Fiber Technologist
Thomas Bregger, Ph.D., Physiologist
J. W. Randolph, M.S., Agricultural Engr.
R. W. Kidder, M.S., Asso. Animal Husb.
C. C. Seale, Associate Agronomist
N. C. Hayslip, B.S.A., Asso. Entomologist
E. A. Wolf, M.S., Asst. Horticulturist
W. H. Thames, M.S., Asst. Entomologist
W. N. Stoner, Ph.D., Asst. Plant Path.
W. A. Hills, M.S., Asso. Horticulturist
W. G. Genung, B.S.A., Asst. Entomologist
Frank V. Stevenson, M.S., Asso. Plant Path.
Robert J. Allen, Ph.D., Asst. Agronomist
V. E. Green, Ph.D., Asst. Agronomist
J. F. Darby, Ph.D., Asst. Plant Path.
H. L. Chapman, Jr., M.S.A., Asst. An. Hush.
Thos. G. Bowery, Ph.D., Asst. Entomologist
V. L. Guzman, Ph.D., Asst. Hort.
M. R. Bedsole, M.S.A., Asst. Chem.
J. C. Stephens, B.S., Drainage Engineer
A. E. Kretschmer, Jr., Ph.D., Asst. Soils
Chem.


SUB-TROPICAL STATION, HOMESTEAD
Geo. D. Ruehle, Ph.D., Vice-Dir. in Charge
D. 0. Wolfenbarger, Ph.D., Entomologist
Francis B. Lincoln, Ph.D., Horticulturist
Robert A. Conover, Ph.Di., Plant Path.
John L. Malcolm, Ph.D., Asso. Soils Chemist
R. W. Harkness, Ph.D., Asst. Chemist
R. Bruce Ledin, Ph.D., Asst. Hort.
J. C. Noonan, M.S., Asst. Hort.
M. H. Gallatin, B.S., Soil Conservationist

WEST CENTRAL FLORIDA STATION,
BROOKSVILLE
William Jackson, B.S.A., Animal Husband-
man in Charge 2

RANGE CATTLE STATION, ONA
W. G. Kirk, Ph.D., Vice-Director in Charge
E. M. Hodges, Ph.D., Agronomist
D. W. Jones, M.S., Asst. Soil Technologist

CENTRAL FLORIDA STATION, SANFORD
R. W. Ruprecht, Ph.D., Vice-Dir. in Charge
J. W. Wilson, Sc.D., Entomologist
P. J. Westgate, Ph.D., Asso. Hort.
Ben. F. Whitner, Jr., B.S.A., Asst. Hort.
Geo. Swank, Jr., Ph.D., Asst. Plant Path.

WEST FLORIDA STATION, JAY
C. E. Hutton, Ph.D., Vice-Director in Charge
H. W. Lundy, B.S.A., Associate Agronomist
W. R. Langford, Ph.D., Asst. Agronomist

SUWANNEE VALLEY STATION,
LIVE OAK
G. E. Ritchey, M.S., Agronomist in Charge

GULF COAST STATION, BRADENTON
E. L. Spencer, Ph.D., Soils Chemist in Charge
E. G. Kelsheimer, Ph.D., Entomologist
David G. A. Kelbert, Asso. Horticulturist
Robert O. Magie, Ph.D., Plant Pathologist
J. M. Walter, Ph.D., Plant Pathologist
Donald S. Burgis, M.S.A., Asst. Hort.
C. M. Geraldson, Ph.D., Asst. Horticulturist
Amegda Jack, M.S., Asst. Soils Chemist


FIELD LABORATORIES

Watermelon, Grape, Pasture-Leesburg
C. C. Helms, Jr., B.S., Asst. Agronomist
L. H. Stover, Assistant in Horticulture

Strawberry-Plant City
A. N. Brooks, Ph.D., Plant Pathologist

Vegetables-Hastings
A. H. Eddins, Ph.D., Plant Path. in Charge
E. N. MeCubbin, Ph.D., Horticulturist
T. M. Dobrovsky, Ph.D., Asst. Entomologist

Pecans-Monticello
A. M. Phillips, B.S., Asso. Entomologist
John R. Large, M.S., Asso. Plant Path.

Frost Forecasting-Lakeland
Warren O. Johnson, B.S., Meteorologist2

1 Head of Department
2 In cooperation with U. S.
3 Cooperative, other divisions, U. of F.
4On leave












CONTENTS


Page


INTRODUCTION


PART I. BOTANICAL CHARACTERISTICS -.


Introduction ....................................


Tung Tree .........................

Botany ...- ..-.... ..-- ......


M u-Oil Tree .......- .........

Botany .................... ...............


Japan Wood Oil Tree .....................

Botany ....................................


Candlenut Tree ................ ......

Botany .............. -- ..--..


Soft Lumbang ...........-..............

Botany .......... .-................ .....


Key to Species of Aleurites .........


Acknowledgment ................ ---


Literature Cited ..............-...........-


-.. ..- ..- ..- .... -.-.. ........ ... ... 5


.....-- ................................ 5


- -..-.-.-..-. ...- .-- ...... ...... ... 5

- --- --- ---- ------- ---- .-.-.-.- ..... 6


.....-.............- ...... ... ......... ... 11

--- --.. -..-.-.-.-..- -......- ...... 12


..-.-......-......-....................... 1

-. --.. -.....- ...- ........ .. 17




............................................ 22



................-.... ............... 26
............. ...... ...... ------------- 27


....... ... .. .. .... .. ... ........... 2 9


. -....-.- .. ..I ...... .........-. .... --. 3 0


......... .... ... ...... ............... 3 0


PART II. CHEMICAL AND PHYSICAL CHARACTERISTICS OF


Introduction ......... .. ....... .. ......-............


M materials ............... -- ..- ....- ..........


M methods ...............- .. ..- ...... .... .....----

Extraction of the Oil ......... ......... ............

Chemical Procedure ...........- .. ....- ... .

Physical Determination ............ ........................


Results .........-....... ------... .... ..........


Discussion ...............--. .- ....-- ..... ....-


Sum m ary ......... .... ............. ...- .. .. ...


Literature Cited ..... ............ ........


THE OILS .......... 31


-....-........-........... 31


.....-...-......-.-.... 33


-.- .....- ... ............. 33

.... ....--...-...... 33

..................... 33

..............-........... 35


.- --...... --......-- .... 35


-......................... 38


---...................... 39


........................... 40








The Genus Aleurites in Florida:

By R. D. DICKEY, SEYMOUR G. GILBERT and CLARE M. GROPP

The genus Aleurites Forst. belongs to the Euphorbiaceae or
spurge family. It includes five species, all of which have been
introduced into Florida. A drying oil, which varies with the
species in its suitability for use in paints, is formed in the seeds
of each species. Tung oil is best known and most widely used.
The purpose of this bulletin is to present (Part I) information
that will aid in the identification of the trees, fruits and seeds
of ,Aleurites and to give the present horticultural status in Flor-
ida of the five species in this genus. Part II presents data on
the chemical and physical characteristics of the oils from these
five species.

Part I. Botanical Characteristics

By R. D. Dickey
INTRODUCTION

Taxonomic characters, such as leaf size and leaf margin, are
quite variable in all species of Aleurites and are influenced by
factors such as age of the tree, fertility of the soil and climate.
For example, one-year-old vigorous seedlings have larger leaves
than mature trees, and some trees in well-cared-for tung or-
chards in the United States are larger (height and spread) than
the size reported for tung trees in China, where they are usually
grown on eroded, rocky hillsides without fertilization.
There is considerable literature on the botany of the five
species of Aleurites. However, some of it is incomplete and
there are several points of disagreement, with the result that
past identifications of some of the species have not always been
accurate.
Measurements of leaves, flowers, fruits and seeds of all species
of Aleurites were taken from trees growing in Florida.

TUNG TREE
The tung tree, Aleurites fordi Hemsl., native to China, is
well known as the principal commercial source of tung oil.
Tung is now grown commercially in China, the southern United
1 Associate Horticulturist, Florida Agricultural Experiment Station.








The Genus Aleurites in Florida:

By R. D. DICKEY, SEYMOUR G. GILBERT and CLARE M. GROPP

The genus Aleurites Forst. belongs to the Euphorbiaceae or
spurge family. It includes five species, all of which have been
introduced into Florida. A drying oil, which varies with the
species in its suitability for use in paints, is formed in the seeds
of each species. Tung oil is best known and most widely used.
The purpose of this bulletin is to present (Part I) information
that will aid in the identification of the trees, fruits and seeds
of ,Aleurites and to give the present horticultural status in Flor-
ida of the five species in this genus. Part II presents data on
the chemical and physical characteristics of the oils from these
five species.

Part I. Botanical Characteristics

By R. D. Dickey
INTRODUCTION

Taxonomic characters, such as leaf size and leaf margin, are
quite variable in all species of Aleurites and are influenced by
factors such as age of the tree, fertility of the soil and climate.
For example, one-year-old vigorous seedlings have larger leaves
than mature trees, and some trees in well-cared-for tung or-
chards in the United States are larger (height and spread) than
the size reported for tung trees in China, where they are usually
grown on eroded, rocky hillsides without fertilization.
There is considerable literature on the botany of the five
species of Aleurites. However, some of it is incomplete and
there are several points of disagreement, with the result that
past identifications of some of the species have not always been
accurate.
Measurements of leaves, flowers, fruits and seeds of all species
of Aleurites were taken from trees growing in Florida.

TUNG TREE
The tung tree, Aleurites fordi Hemsl., native to China, is
well known as the principal commercial source of tung oil.
Tung is now grown commercially in China, the southern United
1 Associate Horticulturist, Florida Agricultural Experiment Station.








The Genus Aleurites in Florida:

By R. D. DICKEY, SEYMOUR G. GILBERT and CLARE M. GROPP

The genus Aleurites Forst. belongs to the Euphorbiaceae or
spurge family. It includes five species, all of which have been
introduced into Florida. A drying oil, which varies with the
species in its suitability for use in paints, is formed in the seeds
of each species. Tung oil is best known and most widely used.
The purpose of this bulletin is to present (Part I) information
that will aid in the identification of the trees, fruits and seeds
of ,Aleurites and to give the present horticultural status in Flor-
ida of the five species in this genus. Part II presents data on
the chemical and physical characteristics of the oils from these
five species.

Part I. Botanical Characteristics

By R. D. Dickey
INTRODUCTION

Taxonomic characters, such as leaf size and leaf margin, are
quite variable in all species of Aleurites and are influenced by
factors such as age of the tree, fertility of the soil and climate.
For example, one-year-old vigorous seedlings have larger leaves
than mature trees, and some trees in well-cared-for tung or-
chards in the United States are larger (height and spread) than
the size reported for tung trees in China, where they are usually
grown on eroded, rocky hillsides without fertilization.
There is considerable literature on the botany of the five
species of Aleurites. However, some of it is incomplete and
there are several points of disagreement, with the result that
past identifications of some of the species have not always been
accurate.
Measurements of leaves, flowers, fruits and seeds of all species
of Aleurites were taken from trees growing in Florida.

TUNG TREE
The tung tree, Aleurites fordi Hemsl., native to China, is
well known as the principal commercial source of tung oil.
Tung is now grown commercially in China, the southern United
1 Associate Horticulturist, Florida Agricultural Experiment Station.





Florida Agricultural Experiment Stations


States, Argentina and Brazil. Recent information on the dis-
tribution of the tung tree and the most important tung oil
producing areas in China is given in the report of the China-
United States Agricultural Mission (1).2 This report gave the
probable native habitat of A. fordi as approximately between
26 and 330 north latitude, in an area comprising 15 provinces
which lie southeast of the great Tsinling mountain range. This
report stated that the leading provinces in the production of
tung oil are Szechwan, Hunan, Kwangsi, Hupeh and Chekiang.
The tung tree is the only species of Aleurites grown commer-
cially in Florida (Fig. 1). Because of climatic limitations, com-
mercial plantings are confined to north and northwest Florida.


2.-Leaves of Aleurites fordi. Left to right, top:
3-lobed; bottom: Four- and 5-lobed leaves.


Entire, 2- and


BOTANY
A discussion of the synonymy of Aleurites fordi Hemsl. and
information on its botany, or both, has been given by Hemsley
(12, 13), Wilson (32), Chun (8), Dickey and Reuther (11),

2 Italic figures in parentheses refer to "Literature Cited" in this bulletin.





The Genus Aleurites in Florida


Newell et al (23), Hoh (14), Mowry (21), West and Emmel
(31) and others.
Description.-A. fordi is a small deciduous tree up to 40 or
or more feet in height with smooth bark and central trunk with
much-branched head. Branches horizontal to semi-erect, often
produced approximately in whorls.
The leaves are glossy, dark green, alternate, long-petioled
and simple. The leaf blades are broadly ovate, 3 to 13 inches
wide, entire with a cordate base and sharp point or with 2
to 5 sharp-pointed lobes. On mature trees most leaves are
entire but occasional ones have 2 or 3 lobes. Four- and
5-lobed leaves are to be found on young, vigorous seedling
trees (Fig. 2). On the petiole near its junction with the leaf
blade are 1 to 4, usually 2
sessile, convex, reddish-brown
glands (Fig. 3). Lobed leaves
usually have a sessile, cup-shaped,
reddish-brown gland at the base
of each sinus.
The flowers are produced in
large panicled cymes at the termi-
nals of shoots of the previous
season's growth, before or as the
leaves unfold, as tree starts
growth in late winter or early Fig. 3.-Petiole glands of
spring (Fig. 4). The flowers of the ileurites fordi (X3).
tung tree are not perfect but are
unisexual. The trees are monoecious, that is, functional stamens
and pistils are produced in separate flowers, but both types of
flowers are borne on the same tree (Figs. 5, 13). The pistillate <
flower, if present, usually is the central or apical flower of the
cyme and all lateral flowers are staminate except on those in-
florescences on which 1 to several pistillate flowers are pro-
duced laterally in a single flower cluster (Fig. 4).
The ratio of pistillate to staminate flowers on an inflorescence
varies widely on seedling trees. There is usually an approxi-
mate ratio of 1 pistillate to 60 staminate flowers per inflor-
escence. Some seedling trees consistently produce very few
pistillate flowers and others comparatively few staminate flowers,
and thus tend to be dioecious. Sepals are 2 to 4, distinct
above but united at the base into a cup-shaped calyx. The petals
are white tinged with red and yellow, darker at the base and





Florida Agricultural Experiment Stations


marked with dark red branched lines running lengthwise (Fig.
5). A prominent tuft of hairs occurs at the base of each petal.
Trees with entirely white or faintly greenish-yellow flowers are
found but do not differ in other known respects from the ordi-
nary seedlings.


Fig. 4.-Inflorescence of Aleurites fordi. It has 5 pistillate flowers;
one is the terminal flower of the central stalk, the others are borne laterally.
One laterally borne pistillate flower can be seen at lower left front of
photograph.

Flowers range from 11/8 to 23/% inches in diameter, with a
mean of 1%, inches. Pistillate flowers are slightly larger (mean
2 inches) than staminate flowers (mean 1%8 inches). Petals
range in number from 4 to 9, usually 5 in staminate
flowers. Pistillate flowers commonly have 7 or 8 petals
(Fig. 5). The stamens are arranged in 3 whorls: the outer-
most consisting of 4 to 8 staminodes; the intermediate
whorl of 5 to 8 distinct, fertile stamens; the inner whorl



























Fig. 5.-Flowers of Aleurites fordi. Top row, pistillate flowers with
5, 6, 7 and 8 petals; bottom row, staminate flowers with 5, 6, 7 and 8
petals.


Fig. 6.-Fruits of Aleurites fordi. Top row, 3- and 4-celled; bottom,
5- and 6-celled fruit.






Florida Agricultural Experiment Stations


of 3 to 8 longer monadelphous fertile stamens. There are
8 to 16 fertile stamens per flower. Pistillate flowers have 4
to 8 staminodes in addition to the pistil. Perfect flowers are
occasionally found.

































Fig. 7.-Fruits and seed. Top row, Aleurites cordata; center, A. montana;
bottom row, A. fordi.

Fruits are 11/2 to 3 inches in diameter, dark green, turning
brown upon maturity (Fig. 6). Tung fruits are quite variable
in shape, most of them being oblate to oblong or ovoid; but
some are nearly spherical and others are inverted pyriform in
outline. Most fruits are more or less necked at the stem end
and nippled at the apex (Fig. 7). The outer hull is fibrous; its
external surface may be smooth or it may be somewhat irregu-






The Genus Aleurites in Florida


larly roughened near the apex; on some, distinct longitudinal
ridges are present. The inner hull is thin and papery.
Each fruit usually contains 3 to 7 large seeds (Figs.
6, 7). Most trees have fruit with 3 to 5 seeds, with 5-seeded
fruit most common. Normal fruits containing 6 and 7 seeds
are infrequently seen. Trees of the Craig type (21) have mal-
formed fruit usually depressed globose or oblate, while some
fruits are kidney-shaped. Up to 22 seeds have been observed
in a single misshapen fruit. The seeds are /8 to 11/4 inches
long, slightly compressed, and have a brown, thin, hard, rough
coat and white flesh (Fig. 7).
The leaves and seeds of the tung tree contain a substance
that is very poisonous to man and animals if eaten.

MU-OIL TREE
The mu-oil tree, Aleurites montana (Lour.) Wils., is native
to South China, neighboring areas in French Indo-China and
Shan States of Burma. The northern range of A. montana
overlaps the southern range of A. fordi and the two trees occur
together in some provinces. McClure (19) stated that Kwangsi
and Kwantung are the principal mu-oil producing provinces of
China. A recent report by the China-United States Agricul-
tural Mission (1) stated that A. montana is native to Kwangsi,
Kwantung, Fukien and the southern parts of Hunan and Che-
kiang provinces. Wilson (32), in 1913, reported that approxi-
mately 10 percent of the Chinese tung oil came from fruit of
this species.
Aleurites montana requires a more tropical climate than A.
fordi, as is indicated by their respective habitats in China. The
mu-oil tree is promising in areas such as Burma, Indo-China
and Nyasaland, where the climate is definitely too warm for
A. fordi. Because of this, the Florida Agricultural Experiment
Station, in cooperation with the USDA Field Laboratory for
Tung Investigations, Gainesville, Florida, initiated tests in 1940
to determine the adaptation of this species to central and southern
Florida. Test plantings were made in several localities over
an area extending from Gainesville to Homestead.
This work was summarized by Dickey, Hamilton and Lagasse
(10) as follows: Though a limited number of the seedlings
planted below Gainesville made fair growth, when considered
from the standpoint of the entire group growth was not satis-
factory. The mu-oil tree has grown vigorously on sandy soils






Florida Agricultural Experiment Stations


at Gainesville. It is less hardy than A. fordi, however, as it was
damaged by low temperatures not affecting the latter. The cold
damage sustained, as with tung, depended mainly on the condi-
tion of the tree as to dormancy at the time cold weather occurred.
The mu-oil tree apparently is not climatically adapted to cen-
tral and southern Florida and is not sufficiently hardy or pro-
ductive to compete successfully with A. fordi in the commercial
tung belt of Florida and neighboring states.
BOTANY
Wilson (32), in 1913, finally cleared up the botanical entangle-
ment which had surrounded this species for many years. Since
then others, including McClure (19), Oudot (24), Wit (33),
Hoh (14), Dickey and Blackmon (9), and Webster (28, 29, 30),
have contributed information on the botany of Aleurites montana
(Lour.) Wils.
Description.-A. montana is a medium to large deciduous tree
up to 60 or more feet in height, with smooth bark. It is upright
in habit, with a strong central trunk from which whorls of
lateral branches arise at regular intervals. Wit (33) and Web-
ster (30) described a second type of branching in which the


Fig. 8.-Leaves of Aleurites montana. Left to right, top: entire, 2-,
3-, 4- and 5-lobed leaves; bottom: 6- and 7-lobed leaves.






The Genus Aleurites in Florida 13

central trunk ceased to exist above the first or second whorl
of branches. Secondary branches arose from the main branches
which produced a tree of low, dense, growth habit. Trees of
the second type have not been observed in Florida.
The leaves are glossy, medium to dark green, alternate, long-
petioled and simple. The leaf blades are broadly ovate, approxi-
mately 3 to 12 inches wide, entire with a cordate or rounded
base and sharp point or with 2 to 7 sharp-pointed lobes
(Fig. 8). Young trees have lobed leaves while mature trees
commonly have entire and lobed leaves on the same tree, often
on the same shoot. Of the leaves that are lobed, those with
3 and 5 lobes are most common. Seven-lobed leaves may
be found on vigorous young trees and vigorous branches of ma-
ture trees. On the petiole near its junction with the leaf blade
are 1 to 3, usually 2, large, green, concave, stalked glands (Fig.
14A). The concave area of the gland is usually reddish brown.
Lobed leaves usually have a sessile, cup-shaped, greenish gland
at the base of each sinus.
The flowers are borne on leafy shoots of the present season's
growth which arise from terminal buds of the previous season's
growth in early spring soon after growth has started (Fig. 9).
Flowers of Aleurites montana are not perfect but are unisexual.


Fig. 9.-Typical staminate (left) and pistillate inflorescences of
Aleurites montana.







Florida Agricultural Experiment Stations


The trees are monoecious, that is, functional stamens and pistils
are produced in separate flowers, but both types of flowers are
usually borne on the same tree (Figs. 10, 13). There are also


Aig. 10.-Flowers of Aleurites montana. Left to right, top: pistillate
flowers with 4, 5 and 6 petals; second row: pistillate flowers with 8 and
7 petals; third row: staminate flowers with 4, 5 and 6 petals; bottom:
staminate flowers with 7 and 8 petals.






The Genus Aleurites in Florida


trees which are entirely or almost entirely staminate or pistillate
(dioecious).
The petals of both staminate and pistillate flowers are white
with a yellowish green area at the base which turns dark red with
age. There is a prominent tuft of hairs at the base of each
petal. There are 2 sepals which are distinct above but united
at the base into a cup-shaped calyx. Flowers range from 1%
to 23% inches in diameter, with a mean of 17/8 inches. Pistillate
flowers are slightly larger (mean 2 1/16 inches) than staminate
flowers (mean 1% inches). Petals range from 4 to 9,
usually 5 in both staminate and pistillate flowers, but flowers
with 6, 7 and 8 petals are more common in pistillate flowers
(Fig. 10). The stamens are arranged in 3 whorls: the outer-
most consisting of 5 to 9 staminodes; the intermediate whorl
of 5 to 8 distinct, fertile stamens; and the inner whorl of
3 to 8 longer monadelphous fertile stamens. There are from
8 to 14 fertile stamens per flower. The anther column is
greenish, becoming dark red with age. Pistillate flowers have
5 to 8 staminodes in addition to the pistil. Perfect flowers are
occasionally found.
The ovary is 3- to 5-celled, usually 3-celled. Fruits are 11/;
to 214 inches in diameter, top-shaped, distinctly 3- to 5-angled,
flattened to slightly depressed at the stem end and pointed at
the apex, light green, turning brown upon maturity. The outer
hull has 3 to 5 longitudinal and many irregular transverse
ridges (Fig. 7). The inner hull contains 3 to 5 seeds and is
extremely hard and woody. The seeds are "% to %/ inch long,
broadly ovoid, compressed, with a brown, thin, hard, slightly
rough coat and white flesh (Fig. 7).
The leaves and seeds of the mu-oil tree contain a substance
that is very poisonous to man and animals if eaten.
Flowering Habit.-Several individuals (9, 14, 24, 27, 28,
29, 30, 33) have contributed information on the flowering habit
of A. montana. Webster (29) clearly described the very variable
and complex flowering habit of this species and his general
classification of inflorescence types is followed.
(1) Male Inflorescences.-As the dormant terminal buds open,
male inflorescences emerge simultaneously with the new leaves
and the individual flower buds form a compact head. The leafy
shoots grow to produce large, much branched, many flowered,
corymbose inflorescences which have about 150 to 500 or even
more male flowers (Fig. 9). Some of the typical male inflor-






Florida Agricultural Experiment Stations


escences may produce one to several female flowers and, when
this is so, these flowers are usually the first to open and some
set fruit.
(2) Female Inflorescences.-These are borne on the current
season's growth but flower buds are not in evidence until the
shoots have grown several inches. The leafy shoots extend to
produce relatively few-flowered, racemose inflorescences which
have about 6 to 40 female flowers (Fig. 9) but female inflor-
escences usually have about 15 to 20 flowers.
(3) Inflorescences Containing Flowers of Both Sexes.-Like
the female inflorescences, these are racemose. The female flowers
usually open before the male ones and therefore all the female
flowers on an inflorescence are open before the first male on
the same inflorescence opens. There are usually fewer male
than female flowers but male flowers may vary in number from
a few to slightly more than the female.
The proportion of staminate to pistillate flowers varies from
tree to tree in seedling populations. Webster (28) observed in
Nyasaland and Burma that two seedling plantings had approxi-
mately 40 percent of trees which were predominantly male.
Oudot (24) reported that 45 percent of seedling trees in a plant-
ing in Indo-China were predominantly male. In Florida several
mature trees have consistently produced a high percentage of
male inflorescences.
At the other extreme there are trees which consistently pro-
duce a high percentage of female type inflorescences. One such
tree, planted at Gainesville, Florida, in 1925, has been examined
11 times since 1936 while in heavy bloom. No staminate flowers
were found during these periodic inspections. Only typical
female inflorescences were produced. Several seedlings of this
parent tree have consistently produced a high percentage of
typical female inflorescences.
Webster (28), in 1941, reported that 27 percent of the trees
in a 123-tree planting had 95 to 100 percent pistillate flowers
and were essentially female trees. Subsequent observations
caused Webster (29), in 1944, to modify his previous statements
slightly. As the heavy bearing trees grew older some of them
produced a larger proportion of staminate flowers than pre-
viously and could no longer be regarded as predominantly female
trees. From 50 to 60 percent of the trees bore a considerably
larger proportion of pistillate flowers than the male trees pre-
viously mentioned and were referred to as "bearing trees."






The Genus Alevrites in Florida


Oudot (24) found that 30 percent of the trees in a 599 tree
planting had 95 to 100 percent pistillate flowers.
All types of intergrading forms exist among trees that are
almost, if not entirely, male or female. The three inflorescence
types are combined in the intergrading forms in every possible
way as to the combination of type and the proportion of each
type of inflorescence on a tree.

JAPAN WOOD OIL TREE
The Japan wood oil tree, Alenrites cordata (Thunb.) Muell.
Arg., is native to central and southern Japan. It grows both
wild and cultivated and the oil is used in Japan in much the
same way as tung oil in China.
Limited trials with A. cordata were initiated at Gainesville,
Florida, in 1943. They indicate that this tree will grow satis-
factorily in that area and that it is as hardy as A. montana or
slightly more so. Its adaptation to central and southern Florida
has not been thoroughly tested but a few trees planted on lime-
rock soils in the Homestead area have grown poorly.
This species offers no commercial possibilities in Florida be-
cause it is less hardy than tung, yields are much lower, and the
oil is of lower quality (see Part II).

BOTANY
The synonymy of Aleurites cordata (Thunb.) Muell. Arg., has
been discussed by Wilson (32) and Legros (17). This species
has been confused with both A. fordi and A. montana and it was
not until 1913 that Wilson (32) pointed out the difference be-
tween the fruit of the Japan wood oil tree and those of the
mu-oil tree and established the latter as a separate species.
Description.-A. cordata is a small deciduous tree up to 35
or more feet in height with smooth bark. It is upright in habit
of growth with a strong central trunk from which whorls of
lateral branches arise at regular intervals.
The leaves are glossy, dark green, alternate, long-petioled
and simple. Usually the petiole and main veins have a decided
reddish tinge. The leaf blades are broadly ovate, approximately
3 to 11 inches wide, entire with a rounded or cordate base and
sharp point or with 2 to 5 sharp-pointed lobes (Fig. 11).
Young trees have lobed leaves, while mature trees have entire
and lobed leaves on the same tree, often on the same shoot.
On mature trees entire and 3-lobed leaves are the types most






Florida Agricultural Experiment Stations


commonly found. On the petiole near its junction with the leaf
blade are 1 to 4, usually 2, small, slender, stalked, reddish
brown glands with slightly convex to flat caps (Fig. 14B).
Lobed leaves usually have a cup-shaped, reddish brown gland,
which is either sessile or stalked, at the base of each sinus.

I


Fig. 11.-Leaves


of Aleurites cordata. Left to right, top: entire, 2- and
3-lobed; bottom: 4- and 5-lobed leaves.


The flowers are borne on leafy shoots of the current season's
growth which arise from terminal buds of the previous season's
growth, in early spring soon after growth has started (Fig. 12).
The flowers of A. cordata are not perfect but are unisexual.
The trees are monoecious, that is, functional stamens and pistils
are produced in separate flowers but both types of flowers are
usually borne on the same tree (Fig. 13). There are also trees
which are entirely or nearly staminate or pistillate (dioecious).
The petals of both staminate and pistillate flowers are white,






The Genus Aleurites in Florida


with a yellowish green area at the base which turns dark red
with age. There is a prominent tuft of hairs at the base of each
petal. There are 2 sepals which are distinct above but united at
the base into a cup-shaped calyx. Flowers range from 12 to 17/
inches in diameter, with a mean of l1/4 inches (Fig. 13). Pistil-
late and staminate flowers of this species are of the same size
(mean 11/ inches). Petals range from 4 to 7, usually
5, in both staminate and pistillate flowers. The stamens
are arranged in 3 whorls: the outermost consisting of 4
to 6 staminodes; the intermediate whorl of 4 to 6 fertile
stamens; the inner whorl of 2 to 6 longer monadelphous
fertile stamens. There are 6 to 11 fertile stamens per flower.
The anther column is yellowish green, becoming dark red with
age. Pistillate flowers have 4 to 6 staminodes in addition to
the pistil.



















Fig. 12.-Typical staminate (left) and pistillate inflorescences of
Aleurites cordata.
The ovary is 3- to 5-celled, usually 3-celled, with a wrinkled
surface. Fruits are 1 to 1 5/16 inches in diameter and 7/ to
1 inch long, distinctly 3- to 5-angled, flattened at both ends,
light green, turning brown upon maturity (Fig. 7). The
outer hull has 3 to 5 small longitudinal ridges and several
small, irregular transverse ones, and is thin, soft and fibrous.
The inner hull is thin, soft and brittle and contains 3 to 5 seeds.
The seeds are 1/2 to %8 inch long, broadly ovoid, compressed,






Florida Agricultural Experiment Stations


with a brown, thin, hard, brittle, smooth coat and white flesh
(Fig. 7).
The leaves and seeds of the Japan wood oil tree contain a
substance which is very poisonous to man and animals if eaten.
Flowering Habit.-The great similarity between the flower-
ing habit of A. cordata and A. montana is apparent from ob-
servations made at Gainesville, Florida, and information in
the literature (17, 27, 32). Three inflorescence types have been
observed.


Fig. 13.-Staminate (left) and pistillate flowers. Top, Aleurites fordi;
center row, A. montana; bottom, A. cordata.

(1) Male Inflorescences.-As dormant terminal buds open,
male inflorescences emerge simultaneously with the new leaves
and the individual flower buds form a compact head. The leafy






The Genus Aleurites in Florida


shoots grow to produce much-branched, many-flowered, corym-
bose inflorescences which have from about 100 to 500 or more
staminate flowers (Fig. 12). Some of the typical male inflor-
escences may produce one to several pistillate flowers and, when
this is so, these flowers are usually the first to open and some
may set fruit.
(2) Female Inflorescences.-They are borne on the current
season's growth but flower buds are not in evidence until the
shoots have grown several inches. The leafy shoots extend
to produce relatively few-flowered, racemose inflorescences which
have from about 6 to 35 pistillate flowers (Fig. 12).
(3) Inflorescences Containing Flowers of Both Sexes.-
Smolsky (27) observed inflorescences having both staminate
and pistillate flowers but did not describe their type. In all
probability they are similar to Type 3 of A. montana.
The proportion of staminate and pistillate flowers varies from
tree to tree in seedling populations. Both male and female in-
florescences are usually present on the same tree but the pro-
portion in which they occur varies widely. Smolsky (27) ob-
served trees which had a high percentage of pistillate flowers
on typical female inflorescences while, at the other extreme,
there were trees which bore a high percentage of staminate
flowers on typical male inflorescences.
Discussion-Wilson (32) pointed out the similarity between
A. cordata and A. montana in size, habit, foliage, general appear-
ance and flowering habit. He gave as diagnostic characters the
differences between the fruit and flowers. Similarities between
these species are evident; of special interest are the distinctive
characters that serve to distinguish them.
Trees of the two species can be differentiated by the fruit.












Fig. 14.-Petiole glands (X3). A, Aleurites montana; B, A. cordata.






Florida Agricultural Experiment Stations


The fruit of A. cordata is very distinct from that of A. montana,
as it is much smaller and the hull is soft and fibrous (Fig. 7).
The leaves of the Japan wood oil tree and the mu-oil tree are
very similar but there are some points of difference which, taken
together, serve to distinguish them. Glands on young leaves of
A. cordata are relatively small, slender and stalked with a slightly
convex to flat, light reddish brown cap, while both young and
old leaves of A. montana have large, stalked, concave, green
glands (Fig. 14). As A. cordata leaves age the glands usually
lose this diagnostic character, as they become concave and are
then indistinguishable from those of A. montana. Both are
easily distinguished from the petiole glands of A. fordi, which
are sessile, convex and dark reddish brown (Fig. 3). Young
leaves of A. cordata have a decided reddish tinge on the petioles
and underside of the leaf blades.

CANDLENUT TREES
The candlenut tree, Aleurites moluccana (L.) Willd. (A.
triloba Forst.), according to Bailey (3, 4) is probably native
to the Malay region but is now widely distributed in the Pacific
Ocean tropics.
Trees of this species have been growing in Florida for several
years and are more susceptible to cold injury than A. fordi,
A. montana or A. cordata. Candlenut trees are now growing
from Merritt's Island south on the east coast and from Tampa
south on the west coast of Florida but specimen plants did not
survive the cold when planted north of these areas. Mature
trees near Melbourne, Florida, were badly injured by a severe
freeze several years ago.
This species has grown vigorously and fruited well in Florida.
It apparently has no commercial possibilities in this state, how-
ever, because candlenut oil is inferior in quality to tung oil
(see Part II). There is no established market for it in this
country and Florida could not compete successfully with coun-
tries growing it, for example, Philippine Islands, Malaya and
Ceylon, where land and labor are very cheap.

BOTANY
A discussion of the synonymy of Aleurites moluccana (L.)
Willd., or information on its botany, or both, has been given
by Mueller (22), Hooker (15), Merrill (20), Hemsley (13),
Bailey (2), Sands (26), Bailey (3, 4), Hoh (14) and others.






The Genus Aleurites in Florida


Description.-A. moluccana is a large evergreen tree growing
up to 60 or more feet in height with central trunk and long
spreading branches.
The leaves are dark shiny green, alternate, long-petioled and
simple. Young leaves are densely rusty pubescent, becoming
nearly smooth when mature. The leaf blades are ovate to ovate-
lanceolate, approximately 3 to 15 inches wide, entire with a
rounded or cordate base and sharp point or with 2 to 5
usually sharp-pointed lobes (Fig. 15). Leaves on young trees
are lobed, while mature trees have both entire and lobed leaves.
On the petiole near its junction with the leaf blade are 2 sessile,
rounded, yellowish or reddish glands (Fig. 16A). Lobed leaves
do not have a gland at the base of each sinus.


Fig. 15.-Leaves of Aleurites moluccana. Left to right, top: Entire,
2- and 3-lobed; bottom: 4- and 5-lobed leaves.

The numerous small flowers are borne in panicled cymes at
the terminals of the current season's wood (Fig. 17). In Flor-
ida flowers may be present almost the year round but heaviest






Florida Agricultural Experiment Stations


flowering occurs during late spring and summer. The flowers are
not perfect but are unisexual. The trees are monoecious, that
is, functional stamens and pistils are produced in separate flow-
ers, but both types of flowers are borne on the same tree. The
inflorescences are either mixed, with both male and female
flowers, or purely staminate, and both types occur on the same
tree. In mixed inflorescences the pistillate flowers are terminal
to the main branches and usually open before the staminate
flowers. There are 2 or 3 sepals which are distinct above
but united at the base into a cup-shaped calyx. The petals of
both staminate and pistillate flowers are white, with a promi-
nent tuft of hairs at the base of each petal. Pistillate and stami-
nate flowers are similar in size and range from /8 to %8 inch
in diameter. Pistillate flowers usually have 5 petals and 5
to 8 gland-like staminodes. Staminate flowers have 4 to 6
petals, usually 5, 5 to 8 gland-like staminodes and 14 to 21
fertile stamens on a convex hairy receptacle. The stamens have
short hairy filaments.









A I'
B

Fig. 16.-Petiole glands (X3). A, Aleurites noluccana; B, A. trisperma.

The ovary is oval, tomentose and 2-celled. The fruits are
2 to 3 inches in diameter, laterally compressed, subglobose,
pubescent, the surface smooth with 4 ridges or shallow
grooves extending from the depressed base to the usually
slightly pointed apex (Fig. 18). The outer hull is fleshy, olive-
green, becoming coriaceous and dark brown upon maturity.
The inner hull is thin, papery and brittle, and contains 1 or
2 seeds. Frequently 1 of the ovules fails to develop, re-
sulting in a fruit with 1 seed. The seeds are 1 to 11/4 inches
long with a thick, very hard, roughly furrowed seed coat and
white flesh (Fig. 18).






The Genus Aleurites in Florida 25

The seed kernels and foliage contain a poisonous substance
and should not be eaten, but the poison is present in considerably
less amounts than in the tung tree.


V


Fig. 17.-Mixed inflorescence of Aleurites moluccana. Pistillate flowers
had opened previously; all open flowers are staminate.





Florida Agricultural Experiment Stations


SOFT LUMBANG
Soft Lumbang, Aleurites trisperma Blanco, is native to the
Philippine Islands, where it is found abundantly in the forests
in many locations.
Trees of this species have been growing in Florida for several
years. They are less hardy, however, than the species previously
g .1


Fig. 18.-Fruits and seed of Aleurites trisperma


S


(left)


and A. moluccana.






The Genus Aleurites in Florida


discussed and are adapted climatically to only the extreme south-
ern part of Florida. Soft lumbang trees on the grounds of the
Sub-Tropical Station, Homestead, withstood the 1945 hurricane
with comparatively little damage, much less than other trees
with the possible exception of palms.
This species is growing and fruiting satisfactorily in Florida
but apparently it has no commercial possibilities here for the
same reasons as the candlenut tree.
BOTANY
A discussion of the synonymy of Aleurites trisperma Blanco,
or information on its botany, or both, has been given by Blanco
(5, 6, 7), Langeron (16), Lynch (18), Merrill (20), Mueller (22),
Pax (25), Sands (26) and others.
Description.-A. trisperma is a medium-sized deciduous tree
up to 45 or more feet in height with smooth bark, central trunk
and much branched head.


Fig. 19.-Leaves of Aleurites trisperma.






Florida Agricultural Experiment Stations


The leaves are glossy, dark green, alternate, long-petioled and
simple, with prominent veins. Young leaves are bronze, be-
coming dark green upon maturity. Leaf blades are broadly
ovate, sharp-pointed, approximately 3 to 12 inches wide, entire
with a cordate base (Fig. 19). On the petiole near its juction
with the leaf blade are 2 glands with short eccentric stalks
and slightly cupped caps (Fig. 16B).
The flowers are produced in large panicles at the terminals




.







-A-





















Fig. 20.-Mixed inflorescence of Aleurites trisperma. Lower left flow-
ers on left branch are pistillate; two flowers on opposite side of branch
are staminate.
W~* Af / '' *f

| ^/ u



Fi.80-Mie Avloecec *f luie "ipra Lo-w" J l ef l
ers on~~V lef ba ch ar 'itlae t w a flwr wpstesd fbac
f:e ^ "* I ^ /ey






The Genus Aleurites in Florida


of shoots of the previous season's growth, before the leaves
unfold, as the tree starts growth in early spring (Fig. 20).
The flowers of A. trisperma are not perfect but are unisexual.
The trees are monoecious, that is, functional stamens and pistils
are produced in separate flowers, but both types of flowers are
borne on the same tree. The inflorescences are either purely
pistillate, purely staminate or mixed, and the three types occur
on the same tree. Mixed inflorescences are most common. There
are 2 or 3 sepals which are distinct above but united at the
base into a cup-shaped calyx. The calyx of pistillate and
staminate flowers is covered with whitish hairs.
Petals are cream-colored, tinged with red on the outside and
with fine red lines running lengthwise on the inside. There is
a tuft of hairs at the base of each petal and the outside of the
petals is covered with silky hairs. Pistillate and staminate
flowers are similar in size and range from 1/2 to 3% inch in
diameter. Pistillate flowers have from 4 to 7 petals, usually
5. Staminate flowers have 4 to 7 petals, usually 5, and 6 to
10 fertile stamens.
The ovary is 3- or 4-celled and covered with silky hairs.
The fruits are 2 to 3 inches in diameter, subglobose to oval,
green, changing to grayish brown upon maturity (Fig. 18).
Most fruits are slightly necked at the stem end and pointed at
the apex. The outer hull is smooth, thin and very brittle.
The inner hull is thin and brittle and contains 3 or 4 large
seeds. The seeds are 7/8 to 13% inches long, ellipical, slightly
flattened, brown, smooth, with a thin brittle coat and white
flesh (Fig. 18).
The foliage and seeds contain a poisonous substance and should
not be eaten.

KEY TO SPECIES OF ALEURITES
A. Foliage evergreen, densely rusty pubescent
when young -...-...---.........-- ......-.... Aleurites mnoluccana
AA. Foliage deciduous, always glabrous.
B. Inflorescene a paniculate cyme arising from
terminal buds of previous season's growth.
C. Leaves always entire, petiolar glands 2,
slightly cupped, stalks eccentric .-.... A. trisperma
CC. Leaves lobed or entire, petiolar glands
2 (1 to 4), convex, sessile ----..--......-....... A. fordi






Florida Agricultural Experiment Stations


BB. Inflorescence corymbose or racemose, on leafy
shoots of current season's growth.
C. Petiolar glands 2 (1 to 3), stalked, large,
green, concave, seeds rough-coated --.. A. montana
CC. Petiolar glands 2 (1 to 4), stalked, small,
brown, convex, seeds smooth-coated ..- A. cordata



ACKNOWLEDGMENT

The author wishes to thank Miss Esther Coogle, staff artist, College
of Agriculture, for preparing the illustrations used in Figs. 3, 14 and 16 of
this bulletin.


LITERATURE CITED

1. ANONYMOUS. The Chinese tung-oil industry. Report of the Chinese-
United States Agricultural Mission. Report No. 2, pp. 129-163.
May, 1947.
2. BAILEY, F. M. The Queensland Flora: Part V, pp. 1434-1435. H. J.
Diddams & Company. 1902.
3. BAILEY, L. H. The Standard Cyclopedia of Horticulture, p. 245, Vol. 1.
The Macmillan Company. 1922.
4. BAILEY, L. H. Manual of Cultivated Plants, p. 620. Revised Edition.
The Macmillan Company. 1949.
5. BLANCO, MANUEL. Aleurites trispenna. Flora de Filipinas, ed. 1,
p. 755. 1837.
6. BLANCO, MANUEL. Aleurites saponaria. Flora de Filipinas, ed. 2, pp.
519-520. 1845.
7. BLANCO, MANUEL. Aleurites saponaria. Flora de Filipinas, ed. 3, vol.
iii, p. 156, pl. 296, 1879; Novissima Appendix, p. 191. 1880.
8. CHUN, WOON YOUNG. Chinese economic trees, pp. 208-210. Commercial
Press, Ltd., 1921.
9. DICKEY, R. D., and G. H. BLACKMON. Propagation, planting and
fertilizing tests with tung oil trees. Fla. Agr. Exp. Sta. Ann. Rept.,
pp. 82-84. 1940.
10. DICKEY, R. D., JOSEPH HAMILTON and F. S. LAGASSE. Cultural re-
quirements of the mu-oil tree. Fla. Agr. Exp. Sta. Ann. Rept., p. 78.
1945.
11. DICKEY, R. D., and WALTER REUTHER. Flowering, fruiting, yield and
growth habits of tung trees. Fla. Agr. Exp. Sta. Bul. 343. 1940.
12. HEMSLEY, W. B. Hooker's Icones Plantarum, xxix. pp. 2801-2802.
1906.
13. HEMSLEY, W. B. Revision of the synonymy of the species of Aleurites.
Bul. Misc. Inf. Royal Botanic Gardens, Kew. 119-121. 1906.
14. HOH, H. C. Genus Aleurites in Kwangtung and Kwangsi, Lingnan Sci.
Jour. 18: 3: 303-327; 4, 513-524. 1939.
15. HOOKER, J. D. Aleurites moluccana. Flora of British India, 5: 384-
385. 1875.
16. LANGERON, MAURICE. Le genre Aleurites Forst., 28-30, 40-41. 1902.
17. LEGROS, J. Cultivation of Aleurites, wood-oil trees. Int. Rev. Agr.;
Mon. Bul. Agr. Sci. and Practice, 26: Pt. 1; 129T-160T; 183T-197T;
237T-251T. Rome. 1935.






Florida Agricultural Experiment Stations


BB. Inflorescence corymbose or racemose, on leafy
shoots of current season's growth.
C. Petiolar glands 2 (1 to 3), stalked, large,
green, concave, seeds rough-coated --.. A. montana
CC. Petiolar glands 2 (1 to 4), stalked, small,
brown, convex, seeds smooth-coated ..- A. cordata



ACKNOWLEDGMENT

The author wishes to thank Miss Esther Coogle, staff artist, College
of Agriculture, for preparing the illustrations used in Figs. 3, 14 and 16 of
this bulletin.


LITERATURE CITED

1. ANONYMOUS. The Chinese tung-oil industry. Report of the Chinese-
United States Agricultural Mission. Report No. 2, pp. 129-163.
May, 1947.
2. BAILEY, F. M. The Queensland Flora: Part V, pp. 1434-1435. H. J.
Diddams & Company. 1902.
3. BAILEY, L. H. The Standard Cyclopedia of Horticulture, p. 245, Vol. 1.
The Macmillan Company. 1922.
4. BAILEY, L. H. Manual of Cultivated Plants, p. 620. Revised Edition.
The Macmillan Company. 1949.
5. BLANCO, MANUEL. Aleurites trispenna. Flora de Filipinas, ed. 1,
p. 755. 1837.
6. BLANCO, MANUEL. Aleurites saponaria. Flora de Filipinas, ed. 2, pp.
519-520. 1845.
7. BLANCO, MANUEL. Aleurites saponaria. Flora de Filipinas, ed. 3, vol.
iii, p. 156, pl. 296, 1879; Novissima Appendix, p. 191. 1880.
8. CHUN, WOON YOUNG. Chinese economic trees, pp. 208-210. Commercial
Press, Ltd., 1921.
9. DICKEY, R. D., and G. H. BLACKMON. Propagation, planting and
fertilizing tests with tung oil trees. Fla. Agr. Exp. Sta. Ann. Rept.,
pp. 82-84. 1940.
10. DICKEY, R. D., JOSEPH HAMILTON and F. S. LAGASSE. Cultural re-
quirements of the mu-oil tree. Fla. Agr. Exp. Sta. Ann. Rept., p. 78.
1945.
11. DICKEY, R. D., and WALTER REUTHER. Flowering, fruiting, yield and
growth habits of tung trees. Fla. Agr. Exp. Sta. Bul. 343. 1940.
12. HEMSLEY, W. B. Hooker's Icones Plantarum, xxix. pp. 2801-2802.
1906.
13. HEMSLEY, W. B. Revision of the synonymy of the species of Aleurites.
Bul. Misc. Inf. Royal Botanic Gardens, Kew. 119-121. 1906.
14. HOH, H. C. Genus Aleurites in Kwangtung and Kwangsi, Lingnan Sci.
Jour. 18: 3: 303-327; 4, 513-524. 1939.
15. HOOKER, J. D. Aleurites moluccana. Flora of British India, 5: 384-
385. 1875.
16. LANGERON, MAURICE. Le genre Aleurites Forst., 28-30, 40-41. 1902.
17. LEGROS, J. Cultivation of Aleurites, wood-oil trees. Int. Rev. Agr.;
Mon. Bul. Agr. Sci. and Practice, 26: Pt. 1; 129T-160T; 183T-197T;
237T-251T. Rome. 1935.







The Genus Aleurites in Florida


18. LYNCH, S. J. Notes on some newer hard-drying vegetable oils; from
Aleurites trisperma Blanco and Garcia nttans Rohr. Proc. Fla. State
Hort. Soc. 57: 152-156. 1944.
19. McCLURE, F. A. Tung oil in the Yangtze Valley. Lingnan Sci. Jour.
9: 3: 233-250. 1930.
20. MERRILL, E. D. A flora of Manila. Bureau of Science, Manila, 290-
291. 1912.
21. MOWRY, HAROLD. Variation in the tung-oil tree. Fla. Agr. Exp. Sta.
Bul. 247. 1932.
22. MUELLER, JEAN (AARGAU). De Candolle Prodromus XV, Pt. 2: 723-
724. 1866.
23. NEWELL, WILMON, HAROLD MOWRY and R. M. BARNETTE: Revised by
A. F. CAMP and R. D. DICKEY. The tung-oil tree. Fla. Agr. Exp. Sta.
Bul. 280. 1935.
24. OUDOT, M. L'Huile de bois de Chine et sa production on Indochine.
L'Agronomie Coloniale 23: 203: 138-147. 1934.
25. PAX, FERDINAND. Das Pflanzenreich 42, pp. 129-131. 1910.
26. SANDS, W. N. Candle-nut and Chinese wood-oil trees. Malayan Agr.
Jour. 12: 1: 1-6. 1924.
27. SMOLSKY, N. V. Suggestions for the selection problem of the tung-oil
trees. Soviet Subtropics. 4: 8: 16-39. 1935.
28. WEBSTER, C. C. A note on the yield of tung trees in Nyasaland. East
African Agr. Jour. 6: 160-163. 1941.
29. WEBSTER, C. C. Observations and experiments on flowering and pollina-
tion of the tung tree. East African Agr. Jour. 9: 3: 136-143. 1944.
30. WEBSTER, C. C. The improvement of yield in the tung tree. Tropi-
cal Agr. 27: 7-12: 179-220. 1950.
31. WEST, ERDMAN and M. W. EMMEL. Some poisonous plants in Florida.
Fla. Agr. Exp. Sta. Bul. 468. 1950.
32. WILSON, ERNEST H. The wood-oil trees of China and Japan. Bul.
Imp. Inst. 11: 3: 441-461. 1913.
33. WIT, F. Het botanisch onderzoek van Aleurites. Landbouw 15: 1:
9-27. 1939.

Part II. Chemical and Physical Characteristics of the Oils
By Seymour G. Gilbert and Clare M. Gropp 3

INTRODUCTION

The development of a program of species evaluation and
cross-breeding within the genus Aleurites requires consideration
of the qualities of the oils of the species and of possible hybrids.
Data on the oil characteristics, as compiled in Table 1 from
Jamieson (2), are incomplete and leave much to be desired.
For example, the iodine numbers given do not permit differ-
entiating the oils of Aleurites montana and A. fordi.
The work herein reported was undertaken with two principal
objectives. The first was to find methods that would clearly
differentiate the oils of these two species. Because of the em-

Formerly associate plant physiologist and agent (junior chemist), re-
spectively, Bureau of Plant Industry, Soils, and Agricultural Engineering,
U. S. Department of Agriculture, Gainesville, Florida.







The Genus Aleurites in Florida


18. LYNCH, S. J. Notes on some newer hard-drying vegetable oils; from
Aleurites trisperma Blanco and Garcia nttans Rohr. Proc. Fla. State
Hort. Soc. 57: 152-156. 1944.
19. McCLURE, F. A. Tung oil in the Yangtze Valley. Lingnan Sci. Jour.
9: 3: 233-250. 1930.
20. MERRILL, E. D. A flora of Manila. Bureau of Science, Manila, 290-
291. 1912.
21. MOWRY, HAROLD. Variation in the tung-oil tree. Fla. Agr. Exp. Sta.
Bul. 247. 1932.
22. MUELLER, JEAN (AARGAU). De Candolle Prodromus XV, Pt. 2: 723-
724. 1866.
23. NEWELL, WILMON, HAROLD MOWRY and R. M. BARNETTE: Revised by
A. F. CAMP and R. D. DICKEY. The tung-oil tree. Fla. Agr. Exp. Sta.
Bul. 280. 1935.
24. OUDOT, M. L'Huile de bois de Chine et sa production on Indochine.
L'Agronomie Coloniale 23: 203: 138-147. 1934.
25. PAX, FERDINAND. Das Pflanzenreich 42, pp. 129-131. 1910.
26. SANDS, W. N. Candle-nut and Chinese wood-oil trees. Malayan Agr.
Jour. 12: 1: 1-6. 1924.
27. SMOLSKY, N. V. Suggestions for the selection problem of the tung-oil
trees. Soviet Subtropics. 4: 8: 16-39. 1935.
28. WEBSTER, C. C. A note on the yield of tung trees in Nyasaland. East
African Agr. Jour. 6: 160-163. 1941.
29. WEBSTER, C. C. Observations and experiments on flowering and pollina-
tion of the tung tree. East African Agr. Jour. 9: 3: 136-143. 1944.
30. WEBSTER, C. C. The improvement of yield in the tung tree. Tropi-
cal Agr. 27: 7-12: 179-220. 1950.
31. WEST, ERDMAN and M. W. EMMEL. Some poisonous plants in Florida.
Fla. Agr. Exp. Sta. Bul. 468. 1950.
32. WILSON, ERNEST H. The wood-oil trees of China and Japan. Bul.
Imp. Inst. 11: 3: 441-461. 1913.
33. WIT, F. Het botanisch onderzoek van Aleurites. Landbouw 15: 1:
9-27. 1939.

Part II. Chemical and Physical Characteristics of the Oils
By Seymour G. Gilbert and Clare M. Gropp 3

INTRODUCTION

The development of a program of species evaluation and
cross-breeding within the genus Aleurites requires consideration
of the qualities of the oils of the species and of possible hybrids.
Data on the oil characteristics, as compiled in Table 1 from
Jamieson (2), are incomplete and leave much to be desired.
For example, the iodine numbers given do not permit differ-
entiating the oils of Aleurites montana and A. fordi.
The work herein reported was undertaken with two principal
objectives. The first was to find methods that would clearly
differentiate the oils of these two species. Because of the em-

Formerly associate plant physiologist and agent (junior chemist), re-
spectively, Bureau of Plant Industry, Soils, and Agricultural Engineering,
U. S. Department of Agriculture, Gainesville, Florida.






















Species


Fordi ..........

Montana ............

Cordata ........

Trisperma ..........

Moluccana ..........


TABLE 1.-OIL CHARACTERISTICS FOR 5 SPECIES OF Aleurites.1


Iodine Thiocyanogen Diene Saponification |
Number Number Number Number


15'-1i72

156-167

148-160

127-164

140-164


82.6-84.7



80.9

69.9-71.2

97.1


68 -70 189-195

190-195

50.3-54.1 189-196

34.9-43.2 190-194

S 190-193


1.5

1.5

1.5

1.4

1.4


N 25
D


100-1.5200

130-1.5190

02 -1.509

929-1.4980

749-1.4783


Specific 25
Gravity 25


0.934-0.937

0.932-0.936

0.934-0.934

0.934-0.937

0.920-0.927


I Compiled from Jamieson (2).


..... ...... ..

....-..-...-..-.. ^






The Genus Aleurites in Florida


pirical nature of certain of the determinations, the second ob-
jective was to collect botanically valid material grown within
a limited geographical area and under comparable conditions
of soil and climate for analysis in a single laboratory. Pre-
liminary studies initiated by Harold M. Sell 4 in 1942 to 1944
had largely attained the first objective and had indicated the
importance of the second. In 1947 the increasing attention
given to economic possibilities of certain species made it ad-
visable to begin an intensive study of oils produced in Florida,
largely from the crop of that year.

MATERIALS
The Aleurites fordi Hemsl. samples were obtained from vari-
ous lots of commercially grown fruit. The Aleurites montana
(Lour.) Wils. and Aleurites cordata (Thunb.) Muell. Arg. sam-
ples were from trees grown on the University of Florida Agri-
cultural Experiment Station grounds at Gainesville; the Aleurites
moluccana (L.) Willd. was from the Sub-Tropical Experiment
Station at Homestead, Florida, and the Aleurites trisperma
Blanco sample from the Krome tree at Homestead.5 Identifica-
tion was made or checked by R. D. Dickey of the Horticultural
Department of the Florida Agricultural Experiment Station.

METHODS
EXTRACTION OF THE OIL
The kernels were separated from the fruit by hand and flaked
on a mechanical flaking machine sharpened and adjusted to
provide flakes of a maximum of 100 microns thickness. Fifty-
gram aliquots were extracted for 24 hours in a soxhlet apparatus
with petroleum ether, the ether being removed in a vacuum
oven at 70' C. over P,05. The P20. was always white at the
end of the drying process, indicating lack of oxidation. Oxidized
oils emit organic compounds which decompose on P205 to form
a black surface. The oils were stored in a vacuum desiccator
in a refrigerator until required for analysis, most determina-
tions being completed within 48 hours after removal of the
solvent.
CHEMICAL PROCEDURE
Iodine numbers were determined by means of the Hanus

4 Formerly associate chemist in BPISAE.
SThe courtesy of Geo. D. Ruehle at Sub-Tropical Experiment Station,
Homestead, in furnishing these samples is gratefully acknowledged.






Florida Agricultural Experiment Stations


official (1) method, the Wijs official (1) and a modified Rosen-
mund-Kuhnhenn method as follows:
Solution.-Pyridine dibromide reagent.
1. Eight grams of bromine is added to 20 ml. of glacial acetic
acid.
2. Ten grams (5.5 ml.) of cone. H.S04 is added to a mixture of
8 gm. of pyridine and 20 ml. of glacial acetic acid while it is
being cooled in an ice bath.
3. The second solution is added to the first slowly and the mix-
ture is cooled after each addition. The solution is then
diluted to one liter with glacial acetic acid, stored in a dry
bottle which was kept in a cool place, and used in less than
a week.
Procedure.-The sample (approximately 50 mg.) is weighed
in a glass cup and placed in an iodine flask with 10 ml. of chloro-
form and shaken to dissolve it. Twenty ml. of pyridine di-
bromide solution is added and the mixture is allowed to stand
in the dark for 30 minutes, with occasional shaking. Five ml.
of fresh 10 percent KI (iodate free) and 40 ml. of H20 are added
quickly. The stopper is replaced in the flask and the flask in-
verted, after which the stopper is washed and the solution is
titrated with N/20 sodium thiosulfate solution. When the solu-
tion becomes straw-yellow, 5 ml. of freshly prepared 2 percent
starch solution is added and the titration is completed. Two
blanks are run in the same manner for each series of determina-
tions. The temperature of the Rosenmund-Kuhnhenn reagent
is kept constant to within 0.100 C. during the interval between
the pipetting of the aliquots and the blank.
The saponification numbers were determined essentially ac-
cording to the AOAC method (1), using 1-gram samples. A
hydrolysis bath large enough for twelve 300-ml. Erlenmeyer
flasks was constructed from sheet metal and heated by a steam
coil to provide uniformity of heating conditions. All joints were
glass to glass (standard taper). Because of the relatively high
coefficient expansion of alcohol, at least two blanks with alco-
holic KOH were run simultaneously with each 10 samples. The
alcohol was of C. P. grade and oxidizing agents were removed
just before use.
Thiocyanogen numbers were determined according to the pro-
cedure recommended by Jamieson (2).
Diene numbers were determined by the Ellis-Jones-McKinney






The Genus Aleurites in Florida


(3) procedure, except that the reaction solution was refluxed
in 300 ml. conical flasks with standard taper joints on a rheo-
stat-controlled hot plate (Precision Scientific Co.) instead of
an oil bath. National Bureau of Standards benzoic acid was
used as a primary standard for all acidimetric work.
Acid numbers were determined on all samples. In material
from previous years some difficulty had been encountered with
samples of Aleurites montana which had high acid numbers.
The material used in the 1947 studies had been stored under
proper conditions (seeds removed from fruit, air-dried, then
stored in laboratory until used) and in no case did any sample
have a measurable acidity (acid number below 0.1 unit).
PHYSICAL DETERMINATION
The specific gravity was determined by the AOAC (1) method.
The dispersion and refractive indices were read on a Bausch
and Lomb Abbe refractometer.
The method for the determination of alpha-eleostearic acid
in tung oil by spectrophotometric measurement (5) was applied
to the determination of alpha-eleostearic acid in all five species.
The extinction coefficient E was obtained from the density
values read on a Beckman, model DU, quartz spectrophotometer,
with Phillips' spectro grade iso-octane as the solvent. Concen-
trations of approximately 5 mg. of oil per liter of solution were
tested and readings were taken from 225 to 355 millimicrons.
The curves obtained are shown in Figure 21.
1 gm./1. 1
The extinction cofficient E gm is based on a light
1 cm.
path of 1 cm. and is obtained by dividing the density as read
by the number of grams of oil per liter of solution. The value
was calculated for the region of maximum absorption in the
solvent used, namely at 270 mu. Samples of alpha-eleostearic
acid were prepared by the method of Nicolet (4). An average
value of E at 270 mp of 167.9 was obtained for our samples.
Since this value was lower than that of O'Conner et al. (5) and
our values declined with time of storage, we have used their
value of E = 169.8 in our calculations.

RESULTS
Chemical Measurements.-The data from the chemical meas-
urements are given in Table 2. The Hanus method gave con-
sistently higher results than the Rosenmund-Kuhnhenn or the
















TABLE 2.-CHEMICAL CHARACTERISTICS OF OIL FROM FIVE SPECIES OF Aleurites DETERMINED FROM EXPERIMENTAL SAMPLES.
Iodin NumbeAlpha-
Iodine Number Thiocyano- Saponifica- Eleostearic
Species gen tion Diene Acid
SRosenmund- Wijs Hanus Number Number Number (Calcu-
Kuhnhenn lated)' %1o

Fordi ...................-... 164.4 168.8 181.8 83.5 195.3 69.3 77.6
Montana .....--- .....---- ..... 153.0 154.6 170.6 78.4 194.8 57.5 64.4
Cordata ... .--.. 144.2 144.9 160.7 80.4 193.9 43.5 48.7
Trisperma ...................... 122.6 127.6 143.8 66.9 195.9 36.0 40.3
Moluccana ................. 145.2 155.7 154.2 98.6 ) 195.2 00.0 00.0

1 The value 89.30 was used as the theoretical for 100 percent of alpha-eleostearic acid glycerides.
CC







The Genus Aleurites in Florida


Wijs method, except for Aleurites moluccana. The agreement
between the last two methods is fairly good, except for A.
moluccana. Here the Wijs and Hanus methods are in good
agreement and higher than the Rosenmund-Kuhnhenn values.
A. moluccana also differs from the other species in having
the highest thiocyanogen number and a diene number of zero.
A. trisperma has the lowest iodine number, the lowest thio-
cyanogen number, and, except for A. moluccana, the lowest diene
number.
The percentage of alpha-eleostearic acid was calculated from
the diene number, using 89.3 as the theoretical value for alpha-
eleostearic from the average of the range reported by Jamieson.
A. fordi has the highest alpha-eleostearic acid content, with
that of A. trisperma roughly only 1/2, A. cordata 2/ and A. mon-
tana 5/6 of that for A. fordi oil.
The saponification numbers show no major differences, except
possibly in a lower reading for A. cordata.
Physical Measurements.-The data on physical characteristics
are given in Table 3. The refractive indices follow the order of
diene number more closely than that of iodine number, the main
difference being in Aleurites moluccana, which has a moderately
high iodine number but the lowest refractive index. The specific
gravity values are fairly close for A. cordata, A. trisperma and
A. moluccana and rise for A. montana and A. fordi in the order
named.


TABLE 3.-PHYSICAL CHARACTERISTICS OF OIL FROM FIVE SPECIES OF
Aleurites DETERMINED FROM EXPERIMENTAL SAMPLES.

I Dispersion
N -1 Alpha-
N 25 I D Specific 25 gm./liter' Eleostearic
Species D | Gravity -- E Acid
N -Nc 250 1 cm. %

Fordi ...... 1.5220 28.0 0.940 144.5 85.0
Montana.. 1.5112 29.0 0.932 114.0 67.0
Cordata .. | 1.5055 30.0 0.924 88.0 51.7
Trisperma 1.4969 35.1 0.927 73.3 43.1
Moluccana 1.4762 37.5 0.923 00.0 00.0

1 At 270 mi.
SCalculated from E270 = 170.0.






Florida Agricultural Experiment Stations


The extinction coefficients were used to plot Figure 21 and
to determine the percentage of alpha-eleostearic acid, based on
the value of E at 270 m/ = 169.8 for the pure acid. The values
obtained for alpha-eleostearic acid content of A. fordi oil agree
well with the diene number reported by McKinney and Jamieson
(2) if their correction for incomplete diene reaction as 86.6
percent of theoretical is used. However, this correction does
not improve the correlation between the calculated alpha-eleo-
stearic acid percentage for the oils of the other species.






li C ontrt
-- ,rdata e- -
Slol.rccnr ra**
















Wave Length
Fig. 21.-Absorption spectra of oils of Aleurites spp.

DISCUSSION

The data on spectral absorption of tung oil (A. fordi) and
alpha-eleostearic acid in iso-octane were in excellent agreement
with those of O'Conner et al. (5). All species except A. moluc-
cana showed the characteristic absorption between 255 and
285 mt of the alpha-eleostearic acids with a peak at 270 me.
Inspection of the tables and the graph shows that on the basis
of alpha-eleostearic acid content, Aleurites fordi and A. montana
are similar in composition. Since both of these oils have been
1z
4- o


4'
























are similar in composition. Since both of these oils have been







The Genus Aleurites in Florida


acceptable as commercial drying oils, those from hybrids would
be expected to be acceptable also. The oils obtained from three
hybrids of Aleurites montana x A. fordi were examined by the
spectrophotometer and E values of 123.4, 115.7, and 121.7 were
obtained. This indicates that such first-generation hybrids tend
to have alpha-eleostearic acid contents approximately midway
between those of the parent species.
Aleurites cordata and A. trisperma were found to have much
lower alpha-eleostearic acid contents than A. fordi and, there-
fore, hybrids between either of these and A. montana or A. fordi
probably would produce oil with a low alpha-eleostearic acid
content. Since A. moluccana has no alpha-eleostearic acid, it
is of doubtful value in a breeding program.
Aleurites moluccana oil showed wide differences in chemical
and physical properties from the other species as a group. In
addition to its lack of alpha-eleostearic acid, the high thio-
cyanogen and iodine numbers point to differences other than
in alpha-eleostearic acid content. The composition of the mixed
glycerides was calculated from the formula given by Jamieson
(2, p. 3986) after substituting glyceride values for the acid values
given. After correcting for saturated acid glyceride and un-
saponifiable matter previously determined as 10 percent of the
oil, the following values for glycerides were obtained: Linolenic
27 percent, linoleic 23 percent and oleic 40 percent. Thus, A.
moluccana oil appears to have a composition more similar to
linseed oil than to A. fordi oil, differing from A. fordi not only
in absence of alpha-eleostearic acid but also in that all double
bonds are non-conjugated.

SUMMARY
Some important chemical characteristics (iodine number, thio-
cyanogen number, saponification number and diene number)
and physical characteristics (refractive index, dispersion, specific
gravity and extinction coefficient on a Beckman spectrophotom-
eter) of the oils from the five species of Aleurites were com-
pared. Aleurites montana oil and oil from Aleurites montana x
A. fordi hybrids are only slightly different in composition from
A. fordi oil. Aleurites cordata and A. trisperma oils contain
considerable alpha-eleostearic acid but are inferior to A. fordi
oil in this respect. Aleurites moluccana oil has no alpha-eleo-

"The equations given by Jamieson on page 397 and 398 have typo-
graphical errors which were corrected before use.







40 Florida Agricultural Experiment Stations

stearic acid but probably has a high percentage of an acid such
as oleic.

LITERATURE CITED
1. Association of Official Agricultural Chemists. Official and tentative
Methods of Analysis. 6th ed. 1945.
2. JAMIESON, GEORGE S. Vegetable fats and oils. Reinhold Publishing
Corp. 2nd ed. 508 pp. 1943.
3. McKINNEY, R. S., N. J. HALBROOK and W. G. ROSE. A study of the Ellis-
Jones maleic anhydride method and its use in testing tung oil. Oil and
Soap 19: 141-143. 1942.
4. NICOLET, B. H. CG8 fatty acids. I. The non-identity of eleostearic acid
tetrabromide from tung oil with ordinary linolic acid tetrabromide. Jour.
Amer. Chem. Soc. 43: 938-940. 1921.
5. O'CONNOR, R. T., D. C. HEINZELMAN, A. F. FREEMAN and F. C. PACK.
Spectrophtometric determination of alpha-eleostearic acid in freshly
extracted tung oil: Determination of extinction co-efficients in oil
solvents. Ind. and Eng. Chem. Anal. Ed. 17: 467-470. 1945.




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