The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
Bulletin 468 March, 1950
UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
WILLARD M. FIFIELD, Director
Some Poisonous Plants
ERDMAN WEST AND M. W. EMMEL
Fi. .-Cocklebur-fruitin branch and three seedlings.
," ' "
i 1 ; in b n
Fig. 1.-Cocklebur-fruiting branch and three seedlings.
BOARD OF CONTROL EDITORIAL
J. Francis Cooper, M.S.A.. Editor3
Frank M. Harris, Chairman, St. Petersburg Clyde Beale, A.B.J., Associate Editor:
N. B. Jordan, Quincy
Hollis Rinehart, Miami ENTOMOLOGY
Eli H. Fink, Jacksonville
George J. White, Sr., Mount Dora A. N. Tissot, Ph.D., Entomologist'
W. F. Powers, Secretary, Tallahassee L. C. Kuitert, Ph.D., Associate
F. A. Robinson, M.S., Asst. Apiculturist
EXECUTIVE STAFF H. E. Bratley, M.S.A., Assistant
J. Hillis Miller, Ph.D., President3 HOME ECONOMICS
J. Wayne Reitz, Ph.D., Provost for
Agriculture Ouida D. Abbott, Ph.D., Home Econ.'
Willard M. Fifield, M.S., Director R. B. French, Ph.D., Biochemist
L. O. Gratz, Ph.D., Asst. Dir., Research
Geo. F. Baughman, M.S., Business Manager' HORTICULTURE
Claranelle Alderman, Accountant'
G. H. Blackmon, M.S.A., Horticulturist'
MAIN STATION, GAINESVILLE F. S. Jamison, Ph.D., Horticulturist3
Albert P. Lorz, Ph.D., Asso. Hort.
AGRICULTURAL ECONOMICS H. M. Reed, B.S., Chem., Veg. Processing
R. K. Showalter, M.S., Asso. Hort.
C. V. Noble, Ph.D., Agr. Economist 1 R. A. Dennison. Ph.D., Asso. Hort.
H. G. Hamilton, Ph.D., Mktg. Economist R. H. Sharpe, M.S., Asso. Hort.
R. E. L. Greene, Ph.D., Agr. Econimist R. J. Wilmot, M.S.A., Asst. Hort.
Zach Savage, M.S.A., Associate R. D. Dickey, M.S.A., Asst. Hort.
A. H. Spurlock, M.S.A., Associate Victor F. Nettles, Ph.D., Asst. Hort.
D. E. Alleger, M.S., Associate L. H. Halsey, M.S.A., Asst. Hort.
D. L. Brooke, M.S.A., Associate C. D. Hall, Ph.D., Asst. Hort.
M. R. Godwin, Ph.D., Associate F. S. Lagasse, Ph.D., Asso. Hort.-
H. W. Little, M.S., Assistant
Tallmadge Bergan, B.S., Assistant LIBRARY
D. C. Kimmel, Ph.D., Assistant
Orlando, Florida (Cooperative USDA) Ida Keeling Creap, Librarian
G. Norman Rose, B.S., Asso. Agr. Economist
J. C. Townsend, Jr., B.S.A., Agr. PLANT PATHOLOGY
J. B. Owens, B.S.A., Agr. Statistician' W. B. Tisdale, Ph.D., Plant Pathologist'
J. F. Steffens, Jr., B.S.A., Agr. Statistician Phares Decker, Ph.D., Plant Pathologist
Erdman West, M.S., Mycologist and Botanist
Howard N. Miller, Ph.D., Asso. Plant Path.
AGRICULTURAL ENGINEERING Lillian E. Arnold, M.S., Ast. Botanist
Frazier Rogers, M.S.A., Agr. Engineer 1 3 Robert W. Earhart, Ph.D., Plant Path.2
J. M. Johnson, B.S.A.E., Asso. Agr.
Engineer POULTRY HUSBANDRY
J. M. Myers, B.S., Asso. Agr. Engineer
R. E. Choate, B.S.A.E., Asst. Agr. Engineer' N. R. Mehrhof, M.Agr., Poultry Hush.1
A. M. Pettis, B.S.A.E., Asst. Agr. Engineer" J. C. Driggers, Ph.D., Asst. Poultry Husb.3
Fred. H. Hull, Ph. D., Agronomist1 F. B. Smith, Ph.D., Microbiologist'
G. E. Ritchey, M.S., Agronomist- Gaylord M. Volk, Ph.D., Chemist
G. B. Kiliger, Ph.D., Agronomist3 J. R. Henderson, M.S.A., Soil Technologist3
H. C. Harris, Ph.D., Agronomist J. R. Neller, Ph.D., Soils Chemist
R. W. Bledsoe, Ph.D., Agronomist Nathan Gammon, Jr., Ph.D., Soils Chemist
W A. ACarver, Ph.D., Associate R. A. Carrigan, Ph.D.. Biochemist3
Darrel D. More, Ph.D., Associate Ralph G. Leighty, B.S., Asso. Soil Surveyor
Fred A. Clark, B.S., Assistant Geoe. D. Thornton, Ph.D., Asso.
Myron C. Grennell, B.S.A.E., Assistant Microbiologist3
M. N. Gist, Collaborator- H. W. Winsor, B.S.A., Assistant Chem'st
R. E. Caldwell, M.S.A., Asst. Chemist3
ANIMAL HUSBANDRY AND NUTRITION V. W. Cyzycki, B.S., Asst. Soil Surveyor
W. L. Pritchett, M.S., Asst. Chemist'
R. S. Glasscock. Ph.D., An. Husbandman3 James H. Walker, M.S.A., Asst. Soil
J. E. Pace, B.S.A., Asst. An. Husbandman Surveyor
S. John Folks, B.S.A., Asst. An. Husb. Walter J. Friedmann, M.S.A., Asst.
T. J. Cunha, Ph.D., Asso. An. Husbandman Biochemist
G. K. Davis, Ph.D., Animal Nutritionist3 O. E. Cruz, B.S.A., Asst. Soil Surveyor
R. L. Shirley, Ph.D., Biochemist
Katherine Boney, B.S., Asst. Chem.
DAIRY HUSBANDRY AND MFS. D. A. Sanders, D.V.M., Veterinarian'
E. L. Fouts, Ph.D., Dairy Technologist M. W. Emmel, D.V.M., Veterinarian3
R. B. Becker, Ph.D., Dairy Husbandman C. F. Simpson, D.V.M., Asso. Veterinarian
S. P Marshall, PhD., Asso. Dairy Husb.3 L. E. Swanson, D.V.M., Parasitologist
W. A. Krienke, M.S., Asso. in Dairy Mfs3 Glenn Van Ness, D.V.M., Asso. Poultry
P. T. Dix Arnold, M.S.A., Asst. Dairy Husb.' Pathologist
L. E. Mull, M.S., Asst. in Dairy Tech. G. E. Batte, D.V.M., Asso. Parasitologist
BRANCH STATIONS SUB-TROPICAL STATION, HOMESTEAD
Ceo. D. Ruehle, Ph.D., Vice-Dir. in Charge
NORTH FLORIDA STATION, QUINCY D. Wolfenbarger, Ph.D., Entomologist
J. D. Warner, M.S., Vice-Director in Charge Francis B. Lincoln, Ph.D., Horticulturist
Milton Cobin, B.S., Asso. Horticulturist
R. R. Kincaid, Ph.D., Plant Pathologist Robt. A. Conover, Ph.D., Asso. Plant Path.
L. G. Thompson, Ph.D., Soils Chemist John L. Malcolm, Ph.D., Asso. Soils Chemist
W. C. Rhoads, M.S., Entomologist R. W. Harkness, Ph.D., Asst. Chemist
W. H. Chapman, M.S., Asso. Agron.
Frank S. Baker, Jr., B.S., Asst. An. Hus. CENT. FLA. STATION, BROOKSVILLE
Mobile Unit, Monticello
R. W. Wallace, B.S., Associate Agronomist William Jackson, B.S.A., Animal Husband-
Mobile Unit, Marianna man in Charge2
R. W. Lipscomb, M.S., Associate Agronomist
Mobile Unit, Chipley
J. B. White, B.S.A., Associate Agronomist RANGE CATTLE STATION, ONA
Mobile Unit, Pensacola W. G. Kirk, Ph.D., Vice-Director in Charge
R. L. Smith, M.S., Associate Agronomist 1. M. Hodges, Ph.D., Agronomist
D. W. Jones, B.S., Asst. Soil Technologist4
E. M. Kelly, B.S.A., Asst. An. Hush.
CITRUS STATION, LAKE ALFRED
CENTRAL FLORIDA STATION, SANFORD
A. F. Camp, Ph.D., Vice-Director in Charge CENTRAL FLORIDA STATION, SANFORD
W. L. Thompson, B.S., Entomologist R. W. Ruprecht, Ph.D., Vice-Dir. in Charge
J. T. Griffiths, Ph.p., Asso. Entomologist J. W. Wilson, Sc.D., Entomologist
R. F. Suit, Ph.D., Plant Pathologist P. J. Westgate, Ph.D., Asso. Hort.
E. P. Ducharme, Ph.D., Asso. Plant Patho.4 Ben. F. Whitner, Jr.,B.S.A., Asst.Hort.
R. K. Voorhees. Ph.D., Asso. Horticulturist
C. R. Stearns, Jr., B.S.A., Asso. Chemist
J. W. Sites, M.S.A., Horticulturist
H. Sterling, B.S., Asst. Horticulturist WEST FLORIDA STATION, MILTON
J. A. Granger, B.S.A., Asst. Horticulturist C. E. Hutton, Ph.D., Agronomist'
H. J. Reitz, Ph.D., Asso. Horticulturist H. W. Lundy, B.S.A., Associate Agronomist
Francine Fisher, M S., Aset. Plant Path.
I. W. Wander, Ph.D., Soils Chemist.
A. E. Willson, B.S.A., Asso. Biochemist
J. W. Kesterson, M.S., Asso. Chemist
R. N. Hendrickson. B.S., Asst. Chemist
Wallace T. Long, M.S.A., Asst. Hort. FIELD STATIONS
J. C. Bowers, M.S., Asst. Chemist
D. S. Prosser, Jr., B.S.. Asst. Horticulturist Leesburg
R. W. Olsen, B.S., Biochemist
F. W. Wenzel, Jr., Ph.D., Supervisory Chem. G. K. Parris, Ph.D., Plant Path. in Charge
Alvin H. Rouse, M.S., Asso. Chemist C. C. Helms, Jr., B.S., Asst. ,Agronomist
H. D. Merwin, Ph.D., Asso. Chemist
H. W. Ford, Ph.D., Asst. Hort. Plant City
L. W. Faville, Ph.D., Asst. Chemist A. N. Brooks, Ph.D., Plant Pathologist
O. J. Burger, M.S., Asst. Hort.
L. C. Knorr, Ph.D., Asso. Histologist Hastings
W. T. Long, M.S.A., Asst. Horticulturist A. H. Eddins, Ph.D., Plant Path. in Charge
E. N. McCubbin, Ph.D., Horticulturist
EVERGLADES STATION, BELLE GLADE Monticello
A. M. Phillips, B.S., Asso. Entomologist2
R V. Allison, Ph.D.. Vice-Director in Charge John R. Large, M.S., Asso. Plant Path.
F. D. Stevens, B.S., Sugarcane Agronomist
Thomas Bregger, Ph.D., Sugarcane Bradenton
J. W. Randolph, M.S., Agricultural Engineer J. R. Beckenhach, Ph.D., Hort. in Charge
W. T. Forsee, Jr., Ph.D., Chemist E. G. Kelsheimer, Ph.D., Entomologist
R. W. Kidder, M.S., Asso. Animal Hush. David G. Kelbert, Asso. Horticulturist
T. C. Erwin, Assistant Chemist E. L. Spencer, Ph. D., Soils Chemist
Roy A. Bair, Ph.D., Agronomist Robert O. Magie, Ph.D., Gladioli Hort.
C. C. Seale, Asso. Agronomist J. M. Walter, Ph.D., Plant Pathologist
N. C. flayslip, B.S.A., Asso. Entomologist Donald S. Burgis, M.S.A., Asst. Hort.
E. H. Wolf, Ph.D., Asst. Horticulturist
W. H. Thames, M.S., Aset. Entomologist Lakeland
W. N. Stoner, Ph.D., Asst. Plant Path. Warren O. Johnson, B.S., Meterologist2
W. A. Hills, M.S., Asso. Horticulturist
W. G. Genung, B.S.A., Asst. Entomologist
C. J. D'Angio, A.B., Asst. Chemist
D. W. Smith, B.S., Asst. Chemist
W. D. Hogan, M.S., Asst. Plant Pathologist 'Head of Department
Daniel W. Beardsley, B.S., Asst. An. Hush. 2 Tn cooperation with U. S.
W. D. Hogan, M.S., Asst. Plant Path. Cooperative, other divisions, U. of F.
K. A. Harris, B.S.A., Asst. Agr. Engineer On leave.
INTRODUCTION ---_ ----5-------- ------------------------------- 5
CONDITIONS UNDER WHICH POISONOUS PLANTS ARE EATEN --_----- 6
DESCRIPTIONS OF POISONOUS PLANTS ---- ------- ------------------- 7
Aleurites fordi Hemsl., tung-tree ...----------_- -------------- 7
Crotalaria spectabilis Roth., crotalaria ---- ---------------------- 10
Datura stramonium L., jimsonweed -------------------------- 13
Daubentonia punicea (Cav.) DC, rattle-box -------- ---- 15
Gelsemium sempervirens (L.) Ait. f. yellow-jessamine -----------17
Glottidium vesicarium (Jacq.) Harper, coffee weed -----------------.. 19
Lantana camera L., lantana _-----_ ------------ -----------21
Melia azedarach L., chinaberry ----. .-..-------- 24
Nerium oleander L., oleander ----- ---------_- --.. ---------. 26
Prunus caroliniana Ait., cherry-laurel ... .-----------._....... 29
Prunus serotina Ehrh., wild cherry ---. --- ---- 29
Pteridium latiusculum (Desv.). Hieron., bracken .----------.-----.. 31
"Ricinus communis L., castor bean ...--------- -.--_. .. ......... 33
Solanum gracile Link, deadly nightshade -..-- .--_-_ 35
Sorghum halepense (L.) Pers., johnson grass -------- 36
Sorghum vulgare L., sorghum ----....------.-- ----.-----.--.--------. 38
Xanthium pungens Wallr., cocklebur -....4.... ..-----------....-. 41
Zephyranthes atamasco Herb., atamasco lily 43
OTHER POISONOUS PLANTS --------.-------------------------- 45
PLANT CAUSING MECHANICAL INJURY --._ ...--.-.--------- .-----.-. ...... 46
ACKNOWLEDGMENT ....-- -.- _-- ..... ..... ....... ..... ...... .. 47
Some Poisonous Plants in Florida
ERDMAN WEST AND M. W. EMMEL
Poisonous plants have been known to man since before the
time of Christ. A number of references in the Bible allude to the
poisonous properties of some plants. In early times, knowledge
of these plants was used largely for ulterior motive, particularly,
before much was known about metallic poisons. As civilization
progressed, knowledge of the poisonous plants has increased, due
largely to the importance of grazing plants in the economy of
In the United States annual losses among livestock caused by
the consumption of poisonous plants has been estimated at many
millions of dollars. It is very difficult to estimate the actual loss
in Florida caused by livestock eating poisonous plants. Losses
have occurred in all parts of the state and in certain instances
have been very severe. The rapid development of the livestock
industry in this state during the past 15 years has placed in-
creased emphasis on the importance of poisonous plants. Losses
from this cause often can be largely prevented, and it is with this
thought in mind that this bulletin is being published.
It is important to realize in dealing with these plants that
publications from other states, while basically correct in the in-
formation contained, do not necessarily reflect conditions in this
state. Many poisonous plants which are of importance in other
states may be of little consequence in Florida; conversely, some
important poisonous plants in this state are not of particular
significance in other states. Also common names of plants often
differ in many states and even localities. The name "coffee bean,"
for instance, is a common name for at least eight plants in va-
rious Southeastern states. Therefore, it is essential that as much
information as possible be at hand regarding these plants in our
Early diagnosis is an important phase in controlling losses
caused by poisonous plants. In cases of suspected plant poison-
ing in livestock a graduate veterinarian, who by training and
experience should be able to give valuable assistance, should be
6 Agrtcultural Experiment Stations
consulted as early as possible. In this way what might develop
into extensive losses often can be reduced to a minimum.
Conditions Under Which Poisonous Plants Are Eaten
Most animals will not eat poisonous plants under normal cir-
cumstances. The following conditions are associated with plant
poisoning in this state.
Starvation.-Well-fed animals receiving a properly balanced
ration seldom voluntarily eat poisonous plants. Plant poisoning
is frequent in range animals grazing on scant range during the
winter months. Under this condition, there is a shortage of suit-
able grazing and animals eat undesirable plants in an effort to
survive. Whenever possible, winter grazing crops should be
planted to supply feedstuff to supplement pasture during periods
Deficient Rations.-Animals receiving a deficient ration,
either improperly balanced or actually deficient in certain re-
quired ingredients, such as often occurs on range, often develop
a craving for the substance they are not getting and will eat un-
desirable plants in an effort to find it. Thus, it is important that
animals receive adequate amounts of proper mineral supplement
in areas where known deficiencies occur.
Overgrazing and Drouth.-Under conditions in which pastures
are overgrazed, either through grazing too many animals on a
given area and thereby creating a shortage of suitable feed or
through grazing them on pastures made short by drouth or other
conditions, plant poisoning frequently occurs. Under these cir-
cumstances, animals attempt to obtain sufficient food and eat
plants they otherwise would not eat. Cyanogenetic plants particu-
larly are potentially dangerous under these circumstances.
Waste and Trash.-Livestock should not be given access to
waste or trash piles, particularly those containing discarded
poisonous plants. For instance, under normal conditions cattle
grazing in tung groves will not eat the foliage of the standing
tree or the fallen nuts. However, if tung branches and nuts are
discarded in a trash pile cattle have been known to consume them
with relish. Oleander and wild cherry are other examples of
poisonous plants usually not eaten in the standing, living condi-
tion but readily eaten when trimmings are discarded in a trash
Some Poisonous Plants in Florida 7
Newly Plowed Areas.-Such areas should be grazed with cau-
tion. Plowing may expose roots which are poisonous.
Dry or Partially Dry Water Holes.-During seasons of drouth
dry water holes should be used with caution. The roots of many
water plants are poisonous. When water holes become dry such
roots often are exposed. Partially dry water holes should be
avoided for the reason that stagnant water often contains vari-
ous types of infectious materials and toxic products from disin-
tegrating plant materials.
Incidental and Curiosity.-Occasionally animals consume poi-
sonous plant materials incidentally. For instance, hay may con-
tain a goodly quantity of bracken or crotalaria. Animals eating
the hay are incidentally poisoned by the bracken or crotalaria.
Hogs grazing on peanuts incidentally consume crotalaria seeds
which have fallen to the ground. Many animals have a certain
amount of curiosity. They may eat the hydrangea bush at the
corner of the house when plenty of desirable food is at hand. Or,
they may "eat through the fence" where pastures are always
greener on the other side.
Unknown.-Occasionally it is impossible to determine why
some animals eat poisonous plants. Animals have been known to
graze on poisonous species of crotalaria even though sufficient
quantities of other forage were available. Many theories have
been advanced but none have been definitely proven.
Under normal conditions plant poisoning by certain specific
plants usually is seasonal. Examples of these are cocklebur and
atamasco lily. However, instances of poisoning by these plants
have been observed where areas infested with them have been
plowed or otherwise disturbed. All poisonous plants are poten-
tially dangerous at all seasons of the year and should be so re-
Descriptions of Poisonous Plants
Tung-Oil Tree, Tung Tree, Tung-Nut
Description.-The tung-oil tree (Aleurites fordi Hemsl.1) is a
small deciduous tree with smooth bark, milky sap, thick twigs
and horizontal branches often produced in whorls. The leaves are
1 The foliage of Aleurites montana (Lour.) Wils., A. moluccana Willd.,
A. triloba Forst. and A. trisperma Blanco grown experimentally in this
country are less toxic than A. fordi in the order named.
8 Agricultural Experiment Stations
alternate, long-stalked and simple. The leaf-blades, 5 to 10 inches
long, are broadly ovate, sharp-pointed, and often exhibit an addi-
tional point on each side of the tip; margins are entire and bases
broad, sometimes rounded. The leaf-stalk bears two reddish or
brownish glands or small knobs close to the leaf-blade. The
flowers are produced in large clusters at the tips of the twigs in
spring before the leaves appear. They are about one inch in dia-
meter, consist of five to seven petals colored pale pink or white,
with deep brownish red lines running lengthwise, and have
reddish brown bases. The flowers are of two kinds, several pis-
tillate (female) flowers and many staminate (male) flowers oc-
curring in the same cluster. The fruits, produced on drooping
stalks several inches long, are nearly globular, two to three inches
Fig. 2.-Tung oil leaf, flowers and fruit.
Some Poisonous Plants in Florida 9
in diameter and dark green, later brown, in color. Each fruit con-
tains three to seven large, hard, rough-coated seeds with white
flesh. (Fig. 2.)
Habitat and Distribution.-The tung-oil-tree, native of China,
has been planted extensively in northern and western Florida as
a source of oil. Stray seeds have produced trees along fencerows,
on roadsides, and in other locations near tung orchards.
Toxicity.-The foliage, sap and fruit, as well as commercial
tung meal, contain a toxic principle, a saponin, which characteris-
tically induces gastro-enteritis in animals to which they are fed.
Commercial tung meal does not contain as much saponin as the
unprocessed fruit; it also contains a second toxic substance as yet
Cases of tung poisoning have been reported in cattle, horses
and chickens. One and three-quarters pounds of foliage will kill
a 500-pound steer. Under the common practice of grazing cattle
in tung orchards, cases of poisoning have never been reported.
All known instances of poisonings from foliage have resulted
from animals having access to discarded broken branches or
Symptoms.-Symptoms of tung poisoning in cattle are not
observed until three to seven days after the foliage has been con-
sumed. Acute poisoning results in death in three to four days,
while chronic cases may linger for 18 to 21 days before death
ensues. Hemorrhagic diarrhea which becomes watery and profuse
is a prominent symptom. Lack of appetite, cessation of rumina-
tion, listlessness, depression and unthriftiness are common symp-
toms. Chronic cases may develop labored breathing, mucous
discharge from the nose, salivation, cracking of the skin of the
muzzle and progressive emaciation.
Prevention.-Animals should not be allowed access to dis-
carded branches of the tung tree. Commercial tung meal, unless
detoxified, cannot be used as a livestock food.
Treatment.-Attempts to treat acute forms of tung poisoning
in cattle are useless. Chronic cases can be treated by the adminis-
tration of emollients and drugs to relieve the inflammation in
the gastro-intestinal tract. Tempting soft feeds can be used to
stimulate the appetite.
10 Agricultural Experiment Stations
Showy Crotalaria, Yellow Crotalaria
Description.-Showy crotalaria (Crotalaria spectabilis Roth.)
is a robust annual plant 3 to 6 feet or more tall, with an erect,
somewhat ribbed stem bearing several stout, ascending branches.
The alternate leaves are short-stalked and simple; the leaf blades,
four to seven inches long, are dark green above, somewhat paler
beneath, elliptic to cuneate, blunt but often tipped with a bristle.
The stipules are leaf-like and nearly one inch long. The yellow
flowers, about one inch across, are pea-shaped and borne in up-
right spikes 8 to 15 inches long at the top of the plant and at
the ends of the branches. The smooth pods, nearly two inches
long, are inflated, light green when young, becoming nearly black
when ripe. The seeds, nearly 1/4 inch long, are black and glossy.
The whole plant is smooth to the touch and waxy so that water
stands in drops on the leaves. (Fig. 3.)
Habitat and Distribution.-Showy crotalaria is widely planted
as a cover crop to enrich the soil and to reduce the population of
root-knot nematode. It occurs commonly also as a roadside plant,
in fencerows, in abandoned fields, around farm buildings, and
about refuse disposal areas. It is seldom found on very wet soils.
It occurs in nearly all parts of the state, but is especially common
in farming communities.
Toxicity.-The alkaloid, monocrotaline, has been isolated
from the leaves, stems, roots and seed; the concentration is high-
est in the seed. Monocrotaline lowers blood pressure and de-
creases the rate and amplitude of the heart beat in experimental
Natural cases of poisoning have been observed in cattle,
sheep, goats, horses, hogs, mules, chickens and turkeys. Nine
pounds of the dried plant will kill a 300-pound steer in approxi-
mately four days. Two grams of ground seed fed daily will pro-
duce acute poisoning in 50-pound hogs in about seven days.
Chickens have been killed in 30 to 60 days by consuming 80 ma-
The frosted, green or dry plant is toxic to all classes of live-
stock if eaten in sufficient quantity.
Symptoms.-Acute poisoning in cattle is marked by depres.
sion, loss of appetite, bloody feces, drooling saliva, nasal discharge
*', b ,- ?
_/1 f(r^^ -^
12 Agricultural Experiment Stations
and a yellowish discoloration of the visible mucous membrances.
Death occurs within 5 to 10 days.
The most common type of poisoning observed in cattle under
field conditions is the chronic form in which animals often die
two to six months after eating the plant. In such cases very
little evidence of illness is observed until 7 to 14 days before
death. The hair coat may appear rough and there may be a
slight unthriftiness. Usually the first marked symptom noted
is bloody feces. The eyes have an anxious or staring appearance.
The animal appears slightly bloated and full in the middle. Loss
of appetite, diarrhea, yellowish discoloration of the visible muc-
ous membranes, partial version of the rectum and general weak-
ness are other symptoms. Before death the animal "goes down,"
due to general weakness, and is unable to stand on its feet.
The symptoms of crotalaria poisoning in sheep and goats are
similar to those observed in cattle. The period of illness, how-
ever, is somewhat shorter.
Hogs often die suddenly of gastric hemorrhage in acute
cases of poisoning. Chronic cases may develop two to four
months after the animals have had access to the plant. Loss of
appetite, general unthriftiness, weakness and occasionally anemia
occur. Hogs on feed fail to gain weight.
Horses and mules have been known to become affected with
crotalaria poisoning as long as nine months after contact with
the plant. The first period of illness usually is marked by a
gastro-intestinal disturbance (colic). Usually there is a diarrhea
and congestion and yellowish discoloration of the visible mucous
membranes. Intestinal movements can be heard at a distance of
15 to 20 feet from the animal. Symptoms of extreme stupor and
depression for a period of two or three days are interspersed with
periods of two to six weeks during which the animal appears im-
proved. During periods of severe illness affected animals walk
listlessly, in circles, and stumble into various objects; they also
push or lean against stationary objects and often meet sudden
death by falling into awkward positions or becoming entangled in
fences so that they cannot extricate themselves. The usual period
of illness is three to four months, although some animals live
much longer. During this period the general condition of the ani-
mal deteriorates and emaciation occurs. Death occurs as the
result of cardiac failure.
Some Poisonous Plants in Florida 13
Chickens and turkeys, particularly poults, often are poisoned
by eating the seed or green plant. Affected birds become listless
and droopy; often there is diarrhea, darkness or paleness of the
comb. Anemia and emaciation usually occur if the period of ill-
ness is longer than two weeks.
Prevention.-Although poisoning by crotalaria may occur at
any time during the year, it is most frequent in the fall when this
plant is green and succulent while other forage is dry and un-
attractive. It should be considered extremely hazardous to per-
mit livestock of any kind to come in contact with this plant. There
is some controversy among laymen as to the toxicity of C. specta-
bilis, as animals have been known to eat it without inducing
illness. Animals having continual contact with the plant some-
times eat small quantities throughout the season and in this way
develop a tolerance to the toxic principle. Some animals will not
eat the plant, others will eat it only when insufficient desirable
forage is available, while others may eat it even though they are
well fed. The development of poisoning is dependent entirely
upon the amount the animal eats.
Once the plant has been allowed to scatter its seed on the
ground, many years are required to exterminate it, as some seed
lie in the soil for years before sprouting. Planting infested areas
in cultivated crops greatly assists in elimination of the plant.
Treatment.-Animals which have developed symptoms of
crotalaria poisoning rarely recover, regardless of treatment.
Jimsonweed, Jimsonweed datura, Jamestown weed, Thorn apple
Description.- Jimsonweed (Datura stramonium L.) is a
large annual weed, three to five feet tall, with several wide-
spreading branches near the top of the stem. The main stem and
branches are smooth and green or purplish. The alternate leaves
are smooth, light green and stalked; the leaf-blades, three to
eight inches long, are thin, ovate to elliptic, pointed at both ends,
and bear large, irregular, sharp-pointed teeth along the margins.
The erect flowers, borne singly in the leaf axils, are short-stalked,
funnel-shaped but flaring out into a five-pointed star and white
or pale bluish-purple in color. The four-celled fruit is a dry, hard
capsule, ovate, green, becoming pale brown, and covered with
hard, sharp prickles. The pod, about one inch long, splits into four
sections, each containing numerous seeds. (Fig. 4.)
14 Agricultural Experiment Stations
Fig. 4-Jimsonweed-flowering shoot with young fruit.
Habitat and Distribution.-Jimsonweed is found nearly all
over the state, but more commonly in the northern areas. It oc-
curs in cultivated fields, gardens, around farm buildings, particu-
larly old barn lots, roadsides and refuse heaps, nearly always on
Toxicity.-Jimsonweed contains the toxic alkaloids, hyoscya-
mine, atropine and scopolamine, about 0.3 percent of the dry
weight of the plant. All parts of the plant, particularly the seeds,
are poisonous. Cattle are poisoned most frequently, but occa-
sionally sheep, horses and hogs are affected. Children have been
poisoned by eating the fruit or sucking the flowers. Ten to 14
ounces of the green plant will produce fatalities in cattle. The
toxicity of the plant is not destroyed by drying and poisoning oc-
Some Poisonous Plants in Florida 15
casionally has resulted from eating the weed mixed with hay.
Cases of poisoning due to ensilage containing the weed have been
Symptoms.-Dryness of mouth, rapid pulse and respiration,
partial blindness and frequent urination or retention of urine are
common symptoms in cattle. Diarrhea, dilation of the pupils of
the eyes and stiffness also have been observed. In the terminal
stages of illness, respiration becomes slow, weak and irregular,
while the pulse becomes rapid and feeble, with death resulting
Convulsive twitching of the entire body is described as an out-
standing symptom in hogs.
Prevention.-The weed has a rank, unpleasant odor and a
strong taste, and animals are not likely to eat it unless confined
to areas where there is little else to eat.
The plants should be cut and burned before the seeds mature.
Grubbing is considered practical when small areas are involved.
Care should be used that the weed is not included in hay.
Purple Rattlebox, Daubentonia, False Poinciana
Description. Rattlebox (Daubentonia punicea (Cav.)
DC.) is a shrub or small tree seldom more than 10 feet in height.
The trunk is slender, stiff and usually crooked, bare below and
dividing into several stiff, widely spreading branches at the top.
The bark on the twigs and trunks is dark gray to black and only
slightly roughened with raised lenticels. The alternate leaves,
four to eight inches long, are stalked and pinnate, with 6 to 20
pairs of leaflets. Each leaflet is one inch or less long, elliptic
with a minute, pointed tip, dark green above, smooth and rather
firm. The flowers, borne in pendant clusters near the tips of the
branches, are sweet-pea shaped, orange to red in color, and nearly
one inch across, on short, slender stalks. The pods, two to three
inches long and 1/ inch wide, are green, turning dark brown on
ripening, slightly flattened, pointed at both ends, and furnished
with four flanges or wings running lengthwise the pod. The
seeds are oblong to subglobose and brown. (Fig. 5.)
Habitat and Distribution.-Rattlebox, a native of Mexico, was
originally planted in Florida as an ornamental, but has become
naturalized in many areas of the northern part of the state. It
16 Agricultural Experiment Stations
Fig. 5.-Rattlebox-flowering shoot and pod.
is most often found around houses, along fencerows and ditch
banks, and in the flood plains of streams.
Toxicity.-The toxic principle is a saponin, the greatest con-
centration being in the seed.
Cases of poisoning have been reported in sheep, chickens and
pigeons. Approximately 50 grams of the plant per hundred-
weight are sufficient to induce fatal poisoning in sheep. Chickens
may be killed by consuming as few as 6 to 18 seeds, while three or
four seeds have been observed to cause death in pigeons.
Symptoms.-The pulse is rapid and fespirations are weak,
irregular and usually labored in poisoned sheep. Death occurs
Some Poisonous Plants in Florida 17
with little or no struggling. Sheep which recover show diarrhea
and depression for several days.
Drooping wings, ruffled feathers, profound depression, gen-
eral debility, unthriftiness, congested comb and profuse diarrhea
are symptoms usually observed in affected chickens.
The period of illness in pigeons is short. The droppings are
scant, watery and greenish. General weakness occurs. Recovery
seldom is observed.
Prevention.-Animals should not be allowed to contact areas
in which the plant grows wild, particularly when there is a
shortage of feed. When the plant is grown as an ornamental
the pods should be picked before the seeds have an opportunity to
shatter on the ground.
Treament.-A saline purgative, followed by stimulants and
soft food, is beneficial.
Carolina-jessamine, Yellow-jessamine, Evening Trumpet-flower
Description.-Carolina-jessamine (Gelsemium sempervirens
(L.) Ait. f.) is a high-climbing, woody vine that often covers the
tops of small trees and bushes but, in the absence of support, may
trail on the ground and produce many slender, more or less up-
right stems. The main stems of large vines are gray and one
inch or more in diameter, but the majority of the branches are
thin, wiry, much branched and tangled, glossy and dark reddish-
brown in color. The short-stalked leaves are simple and always
produced in pairs; the leaf-blades, 1/ to 21/ inches long, are ovate
to lanceolate, not very sharp-pointed, rounded at the base, smooth
on the margin and dark green, though often marked with ir-
regular reddish-brown discolorations, especially in winter. The
clear yellow, sweet-scented flowers, produced in late winter and
early spring, are borne in small clusters in the leaf axils of the
slender twigs in such profusion as to form conspicuous masses of
color. The individual flowers, tubular with five flaring lobes, are
1 to 11,/ inches long. The seed pods are brown, flat, less than one
inch long and contain several small, winged seeds. (Fig. 6.)
Habitat and Distribution.-Carolina-jessamine grows abun-
dantly in open hammocks, but is also found in thickets, swamps
and open fields, along fencerows, around stumps, and on rocky
bluffs. The vine is most widely distributed in northern Florida,
but occurs as far south as Osceola County.
18 Agricultural Experiment Stations
Fig. 6.-Carolina jessamine-flowering stems with fruits.
Toxicity.-Yellow-jessamine contains the crystalline alka-
loid gelsemine and the amorphous alkaloids gelseminine and gelse-
moidine. Other alkaloids have been reported isolated from the
plant. These alkaloids constitute the poisonous principles in the
plant. They chiefly depress and paralyze motor nerve endings.
Depression of the motor neurons of the brain and spinal cord re-
sult in respiratory arrest.
The flowers, leaves and roots contain the toxic alkaloids, the
greatest concentration being in the roots from which extractions
have been made for medicinal purposes.
Some Poisonous Plants in Florida 19
Cattle, sheep, goats, swine and horses have been reported
poisoned by yellow jessamine. Poisoning of cattle by this plant
is of considerable importance in the Southeastern states, partic-
ularly during the winter months when there is a shortage of de-
sirable green feed.
Single dosages of five pounds of green leaves to a 400-pound
steer did not produce typical poisoning attributed to yellow-jessa-
mine as observed in the field. The feeding of 180 grams of fresh
green leaves to hens over a period of 15 days resulted in death in
20 to 26 days, with no indications of symptoms until four or five
days before death. This would indicate that the poisonous prin-
ciple is cumulative and that animals must eat the plant over a
period of time before poisonous effects are observed.
Symptoms.-Under range conditions animals poisoned by this
plant usually are not found until they are "down." Early symp-
toms consist of muscular weakness, staggering gait and dila-
tion of the pupils of the eyes. As weakness progresses rapidly
the animal "goes down" and death usually occurs in 24 to 48
hours. During this terminal period convulsive movements of the
head and legs occur frequently. The pulse is feeble, respirations
are reduced and the temperature usually is subnormal. Animals
in this condition should not be drenched, as paralysis of the
throat often occurs, resulting in an inability to swallow. Death
occurs from respiratory failure.
Prevention.-Animals should not be allowed to graze in areas
where pasture is scant and yellow-jessamine is plentiful. Grub-
bing is a means of eliminating isolated plants. When larger
areas are involved, fencing off or bulldozing can be an effective
Bagpod, Bladderpod, Coffeeweed, Coffeebean
Description-Bagpod (Glottidium vesicarium (Jacq.) Har-
per) is a robust annual weed, often 6 feet and sometimes 12 feet
high in rich soil. The stems are straight, erect, slender for their
height and branched above the middle with several stiff, wide-
spreading branches, the number depending upon the amount of
competition with other plants. The alternate leaves are widely
spaced on the stem, 4 to 10 inches long, pinnate with 10 to 26 pairs
of leaflets. Each leaflet is elliptic with a small pointed top, 19 to
20 Agricultural Experiment Stations
1 inch long, about 1/ inch wide, dark green above and paler be-
neath, very smooth and waxy. The flowers, borne in clusters of
two to five or more on slender stalks three to five inches long, are
sweet-pea shaped, about 1/ inch across and yellow striped with
pink or entirely red all over. The pods, which persist long after
the leaves have fallen, are 2 to 3 inches long, elliptic, pointed at
both ends and bulged over each of the two seeds. At maturity
the outer layer of the pod opens and exposes the thin, silky,
white sack-like inner layer enclosing the seeds. The seeds,
nearly 1 inch long, are oblong and greenish brown. (Fig. 7.)
Habitat and Distribution.-Bagpod occurs nearly all over
Florida. It is found most commonly in old fields, especially on
rich, damp soil, along ditches and streams, around lakes and sa-
vannahs and sometimes on higher land in abandoned cultivated
Fig. 7.-Bagpod-pods, leaf and flower.
Some Poisonous Plants in Florida 21
Toxicity.-The toxic principle of bagpod is a saponin, a sub-
stance which causes intense inflammation of the gastro-intestinal
Cases of poisoning have been reported in chickens, sheep and
cattle. Approximately 150 mature seeds constitute a fatal dose
for an adult chicken. The green seeds are considerably more
toxic than mature seeds. About five pounds of the green plant
and seeds are required to induce fatal poisoning in a 250-pound
Symptoms.-In affected chickens the comb becomes dark and
congested. A yellowish diarrhea develops. Emaciation and un-
thriftiness occur when the period of illness is prolonged. Bagpod
seeds are found in the crop and gizzard of poisoned birds.
Symptoms of poisoning in cattle and sheep are similar.
Marked depression and sluggishness are among the early symp-
toms when diarrhea occurs. The animal urinates frequently.
Respirations are shallow and accelerated. Depression increases
and finally the animal passes into a comatose condition and death
Prevention.-Chickens most commonly are poisoned by the
seeds which fall from the plant during the winter. The weeds
should be mowed in the late summer or before the seeds mature.
Description.-Lantana (Lantana camera L.) is a shrub or, in
the northern areas, an herbaceous perennial plant reaching a
height of three to five feet. The stems are widely branched,
brittle at the joints, usually bluntly square, green or brown and
armed with weak, sharp spines. The leaves, borne in pairs or
whorls of three, are stalked and aromatic when crushed; the leaf-
blades are ovate or elliptic, somewhat pointed at both ends, dark
green above and paler below, one to three inches long and toothed
along the margin. The flowers, creamy white, yellow or pink,
changing to orange or scarlet, are borne in long-stalked clusters
about one inch across in the axils of the leaves. The individual
flowers have four lobes or divisions and are tubular in the lower
part. The fruits, green to blue or black, are nearly 1/4 inch in
diameter and contain one bony seed. (Fig. 8.)
22 Agricultural Experiment Stations
Fig. 8.-Lantana-flowering shoot with fruit.
Some Poisonous Plants in Florida 23
Habitat and Distribution.-Lantana has been planted widely
as an ornamental and is most common around gardens and old
home sites. It is also found along fencerows, in fields and the
margins of woods. It is found nearly all over the state but is
most common from Orlando southward.
Related Species.-Three other species are common in Florida.
L. aculeata L. grows as high as eight feet, has strongly spiny
stems and yellow flowers, changing to orange or purple. L. ovati-
folia Britton has unarmed stems about five feet or less high and
yellow, unchanging flowers. L. sellowiana Link and Otto has
weak, unarmed stems up to five feet in length and purple flowers.
These species probably are equally toxic.
Toxicity.-This plant contains a substance which sensitizes
the skin of cattle and sheep which have eaten it to sunlight,
causing the skin to become hard, swollen, cracked and painful.
This process is called photosensitization. Plants having this
action may be eaten and the animal sensitized but lesions will not
develop unless exposure to sunlight follows. Experiments indi-
cate that the feeding of 3% to 1 pound of mature dried leaves
will induce poisoning in a 400-pound steer.
Symptoms.-The acute type of poisoning is induced when ani-
mals eat a considerable quantity of the plant. The affected ani-
mal shows symptoms of sluggishness or extreme weakness; the
stools usually are soft and bloody; food is refused; occasionally
partial paralysis of the legs occurs; death usually occurs within
three to four days.
Chronic cases of lantana poisoning are induced when smaller
amounts of the plant are eaten. Affected animals usually be-
come constipated, particularly in the early stages of poisoning,
although later the stools may become soft. Areas of skin and
mucous membrane show a yellowish discoloration. Although
white or non-pigmented skin shows the first evidence of disease,
pigmented skin often subsequently becomes involved. The skin
of the muzzle, ears, neck, shoulders, legs, udder or other part of
the body becomesyellow, swollen, hard, cracked and painful. The
skin often peels, leaving large exposed raw areas.: The skin of
the muzzle usually is extensively involved. Areas of inflammation
extend to the adjacent mucous membranes of the mouth.. and
nasal passages. The skin of the muzzle becomes yellowish to or-
ange in color; it then becomes dry, hard, painful and finally
24 Agricultural Experiment Stations
cracks. The skin may become detached, leaving large bleeding
areas exposed. Bacterial infection may occur in such areas and
extend into the surrounding tissue. Ulcers often develop on the
tongue, gums and the lining of the cheeks. Affected animals
refuse food; saliva drools from the mouth; loss of flesh occurs.
The skin and membranes surrounding the eyes may become
affected, as well as the eyeball itself.
Prevention.-Lantana poisoning most frequently occurs as a
result of a lack of desirable forage. The crushed leaves have a
pungent odor and taste and animals will not eat them if sufficient
suitable forage is available. Animals unfamiliar with the plant
occasionally become poisoned when moved to pastures in which
it is growing. In most instances it is probably practical to
remove the plants by grubbing.
Treatment.-Affected animals should be kept in darkness or
shade, out of contact with sunlight. Soft laxative feeds should
be supplied. Affected skin areas should be treated with mild anti-
septics and healing ointments. The percentage of recoveries
usually is not large, even though many times the symptoms
appear mild. Lesions should be closely observed for screwworm
infestation and treated accordingly.
Chinaberry, China-tree, Pride of India
Description. Chinaberry (Melia azedarach L.) is a small
tree 20 to 40 feet high. The trunk is one to two feet in diameter,
large in proportion to rest of the tree, often divided near the base
into several large branches. The bark is gray to dark gray-
brown, roughened by narrow inter-lacing shallow furrows and
broad flat-topped ridges. The alternate leaves, one to three feet
long, roughly triangular in shape, are twice divided into numer-
ous leaflets. The leaflets, one to two inches long, are broadly
lanceolate or ovate in shape, dark green above and paler beneath,
and sharply toothed or lobed along the margins. The fragrant
flowers are produced on long-stalked, much-branched axillary
clusters soon after the leaves attain full size. Each flower is
about one inch across and composed of five or six narrow purplish
petals surrounding a pale column of stamens. The fruit is
smooth globular, yellow, about inch in diameter. The one
large stone, covered by thin pulpy flesh, is strongly ribbed length-
wise and contains five or six seeds in small cavities.
Some Poisonous Plants in Florida 25
Habitat and Distribution.-Chinaberry is native to Syria,
Iran and northern India but it has been naturalized almost
throughout Florida. It is also common in hammocks and around
abandoned home-sites. (Fig. 9.)
Melia azedarach L. var. umbraculifera Sarg., the umbrella
chinaberry, is a small tree with dense, much branched, umbrella-
shaped crown. It is frequently planted as an ornamental in door-
Toxicity.-The toxic principle of chinaberry has not been de-
termined. Poisoning occurs most frequently among hogs from
eating the green and ripe berries. The lethal dose for a 50-pound
pig is approximately 150 grams of berries. The fruit is less toxic
for goats, chickens and ducks. While the fruits or berries are
Fig. 9.-Chinaberry-flowering shoot and cluster of old fruits.
26 Agricultural Experiment Stations
most toxic, the flowers, leaves and bark also contain the toxic
Symptoms.-In hogs symptoms occur three to four hours
after the berries have been consumed. Loss of appetite, constipa-
tion, blood-stained stools, stiffness, lack of coordination and gen-
eral weakness are the chief symptoms. Death often occurs
within 24 hours.
Prevention.-Animals, and particularly hogs, should not have
access to the fruit of the chinaberry tree.
Treatment.-Berries of the chinaberry are almost always
found in the stomach or intestines of animals poisoned by this
plant. There is no specific treatment. Affected animals usually
die within a short time after symptoms are noted; those which
survive this period usually do so without treatment.
Description. Oleander (Nerium oleander L.) is a woody
shrub or small tree ranging in height from 5 to 25 feet. When al-
lowed to grow naturally, it produces a large number of stems and
forms a dense clump, but occasionally plants are trimmed to a
single large trunk with a much-branched crown. The bark on
young stems is smooth and green but older branches and trunks
are gray and roughened by many raised lenticels. The numer-
ous short-stalked leaves are borne in pairs or more often in
whorls of three around the twigs; the leaf-blades, simple, narrow,
evergreen, leathery, pointed at the tip, dull dark green above with
a prominent lighter colored midrib, are 3 to 10 inches long and
smooth on the margin. The leaves usually turn yellow before
falling and the leaf-scars are prominent on twigs and branches.
The flowers, produced in early summer or all year in the warmer
parts of the state, are borne in upright clusters at the ends of
branches on the upper part of the shrub. They vary in color from
white through pink, creamy yellow and rose to deep red. Nor-
mally there are five petals about one inch long with a fringed ap-
pendage at the base of each, but many cultivated forms with
double (many petalled) flowers are found in gardens. The pods,
not commonly produced, are long, narrow, cylindrical and paired.
The numerous seeds are furnished with a tuft of brown hairs. All
parts of the plants, but especially the new growth, exude a
gummy, sticky sap when injured. (Fig. 10.)
Some Poisonous Plants in Florida 27
Fig. 10.-Oleander-flowering shoots.
Habitat and Distribution.-Oleander, an exotic plant, is found
only where it has been planted, but it has been widely used for
hedges, screen plantings and as an ornamental. Since it grows
vigorously, it must be pruned often and the clippings frequently
find their way to rubbish piles and dumping grounds.
Toxicity.-Two toxic glucosides with properties similar to
those of the digitalis glucosides have been isolated from oleander.
Cases of poisoning have been reported in all classes of livestock,
as well as in humans. Approximately 15 to 20 grams of the green
leaves are sufficient to induce death in mature cattle and horses.
The dry leaves are almost as toxic as the green ones.
Symptoms.-The symptoms of poisoning in horses, cattle and
sheep are rather similar. Affected animals become weak. The
28 Agricultural Experiment Stations
pulse is rapid. Profuse sweating occurs. Purging usually is
present during the entire period of illness. Abdominal pains
often are severe. The extremities are cold. Blood often appears
in the stool in the terminal stages.
Prevention.-The leaves of oleander are fibrous and tough.
Animals will not eat them unless there is a shortage of desirable
Treatment.-Affected animals can be treated by a veterinarian
according to the symptoms shown, but if a lethal dose has been
consumed treatment is of little avail.
Fi. 11.-Laurel cherry-flowering and fruiting shoots.
Fig. ll.--Laurel cherry--flowering and fruiting shoots.
Some Poisonous Plants in Florida 29
Carolina Laurel-cherry, Cherry-lapirel, Mock Orange
Description.-Laurel-cherry (Prunus caroliniana Ait.) is a
shrub or small tree sometimes reaching a height of 25 feet. The
trunks are nearly black, dull, crooked, and often bear many lat-
eral branches. The alternate leaves are short-stalked and
simple; the leaf-blades, two to four inches long, are elliptic,
pointed at both ends, very glossy on the upper side, and bear few
to many sharp teeth along the margins. The pinkish white
flowers appear in late winter or early spring in thick racemes one
to two inches long in the axils of the leaves. The individual flow-
ers, about 1/4 inch in diameter, bear five small round petals. The
fruits, bluish-black to black and nearly 1/_ inch in diameter, are
borne in clusters of two to five, often persisting until the flowers
of the following season appear. Each fruit contains one round
stone covered with dry, purplish flesh. The leaves, twigs and
kernels smell strongly of peach-kernel odor when crushed. (Fig.
Habitat and Distribution.-Laurel-cherry is commonly used
as a hedge plant around homes and to mark driveways. It also
occurs in thickets at the edges of woods and hammocks and along
fencerows. It is found all over the state.
Toxicity.-See discussion under black cherry (next section)
Black Cherry, Wild Cherry, Wild Black Cherry, Rum Cherry
Description.-Black cherry (Prunus serotina Ehrh.) is a
medium to large native tree, sometimes becoming 100 feet tall
and five feet in diameter, but small specimens are more common.
The bark on the trunk and branches is smooth, glossy, reddish
brown to black and marked with numerous lines running around
the branches. On old trunks the bark becomes dull, black and
broken into blocks or ridges. The alternate leaves are slender-
stalked and simple; the leaf-blades, two to six inches long, are
slightly leathery when mature, elliptic, pointed at both ends or
rounded at the base, and have numerous small stiff teeth along
the margins. The leaves fall early in the autumn, often assum-
ing bright red or yellow colors at that season. The small white
flowers are produced early in spring on short lateral twigs bear-
ing one to two small leaves and 20 or more stalked flowers. Each
30 Agricultural Experiment Stations
flower, about 1/2 inch broad, bears five small round white petals.
The fruits are glossy dark purple to black when ripe and each
contains one hard, nearly round stone embedded in juicy, purple
flesh which is edible and has a sweet acid flavor. When the leaves,
twigs or kernels are crushed, they emit the odor of peach-kernels.
Habitat and Distribution.-Black cherry is found as scattered
individuals, seldom in pure stand, from Orange County north and
west to the boundaries of the state. Trees are common along
fencerows where birds have distributed the seeds, as well as in
Fig. 12.--Wild Cherry-leaf, flowering shoot and fruit cluster.
Some Poisonous Plants in Florida 31
hammocks, open woods and pastures. In some areas the tree is
best known for its medicinal bark and valuable cabinet wood.
Toxicity.-Black cherry contains the cyanogenetic glucoside,
amygdalin, which, upon being hydrolyzed by enzymes in the
plant, yields hydrocyanic acid. Poisoning frequently occurs from
eating the young shoots or broken or discarded branches. The
leaves, bark and stones of the fruit contain the glucoside. Young
leaves are considered more toxic than mature ones. (See discus-
sion under sorghum.)
Eastern Bracken, Brake, Brake Fern, Hog Brake, Upland Fern
Description. Bracken (Pteridium latiusculum (Desv.)
Hieron.) is a coarse, herbaceous fern with long, stout, under-
ground rootstocks or stems. The roostocks, often 10 feet long,
are black or dark brown, 1/ inch or more in diameter and some-
times branched. The leaves, with stalks one to three feet long,
are produced singly from the joints of the rootstock so that they
occur in lines or rows; the leaf-blades, one to three feet across
and roughly triangular in shape, are divided into three main seg-
ments, each of which is twice divided into smaller parts and fin-
ally the leaflets; the leaflets are very numerous, oblong or nar-
rowly triangular, light to dark green in color and turned down at
the edges. The young leaves are coiled at the top of the develop-
ing leaf-stalk. There are no flowers. The spores or reproductive
bodies, borne in a line of tiny sacs (sporangia) along the edge of
the lower side of the leaves, are dust-like and light brown in color.
Habitat and Distribution.-Bracken occurs in open, sandy
areas, pastures, open woods, rocky fields, and sometimes in open
spaces in hammocks. It is common over most of Florida as far
south as Lake Okeechobee.
Toxicity.-The toxic principle of bracken is unknown. Cases
of poisoning have been observed in cattle, horses and chickens.
Drying does not destroy the toxicity of the plant. Therefore, hay
and bedding contaminated with the fronds are dangerous. The
toxic principle has an accumulative action. One heavy feeding on
the fronds will not cause poisoning. Typical bracken poisoning
is caused by animals eating three or four pounds of the fronds
daily; illness develops three or four weeks later
Symptoms.-Cattle affected with bracken poisoning usually
have a high temperature, stand with head down and drool.
32 Agricultural Experiment Stations
Bloody fluid trickles from the nostrils. Blood appears in the
feces, either as black masses or bright red clots. The pulse
becomes fast and weak, while respiration often is labored. Death
often occurs within 48 hours after the onset of symptoms.
--" -,' o brc--en. ,
"* s -. 1 '- 1 "-
Fig 13,-Leaf ,of bracken.
Some Poisonous Plants in Florida 33
An unsteady gait usually is the first symptom observed in
horses affected with bracken poisoning. They become drowsy,
push the head against solid objects, and often have difficulty in
swallowing. From 7 to 20 days after the onset of symptoms, the
animal "goes down." General weakness increases and death
occurs in several days, even though the animal may regain its
Prevention.-As a general rule animals eat bracken only
when starving, on inferior forage, or on overgrazed pastures. Hay
containing bracken should not be fed. Bracken areas in pastures
should be plowed and reseeded.
Treatment.-Some animals recover if treatment is adminis-
tered early. Saline purgatives or linseed oil should be given.
Affected animals should be kept in a quiet place. Soft laxative
feeds are beneficial.2
Castor-bean, Palma Crista, Castor-oil Plant
Description.- Castor-bean (Ricinus communis L.) is a ro-
bust annual herb (or small tree southward). The strong stems,
4 to 10 feet high, are erect, often crooked, green or red to purple
and sometimes covered with a white, waxy coating. The alter-
nate leaves, 4 to 30 inches across, are simple and borne on long,
stiff stalks; the leaf-blades are thin with prominent ribs, green
or reddish, star-shaped with five to nine or more lobes, thin and
finely toothed along the margin. The stalk is attached to the
leaf-blade some distance in from the edge. The flower clusters
are produced at the ends of branches but because lateral branches
grow past them, they appear lateral. The flowers, produced in
narrow, upright clusters 6 to 12 inches long, are greenish white
or reddish brown, about 1/2 inch across and lack petals. The
fruits are erect, oval, green or red and covered with stiff, fleshy
spines. The seeds, three in each pod, are about 1/3 inch long,
elliptic, black, white or mottled with gray, black, brown and
white. (Fig. 14.)
Habitat and Distribution.-Castor-bean, a native of the
tropics, has been widely planted as an ornamental and to a less
extent as a crop plant. From these plantings, seeds have been
SRecent reports in literature indicate that repeated doses of thiamine
hydrochloride injected intravenously or intramuscularly are of considerable
benefit in alleviating symptoms of bracken poisoning.
34 Agricultural Experiment Stations
/ 7 -
Fig. 14.-Castor-bean-flowering shoot, leaf, fruits and seed
scattered widely all over Florida. It is common on rich soil in
gardens, around dumping grounds and in the Everglades around
Toxicity.-Castor-bean contains a poisonous principle, ricin,
which is a true protein.
All parts of the plant, particularly the beans, are toxic for all
classes of livestock. Castor pomace contains the toxic principle
and should not be used as feed for livestock.
Symptoms.-The symptoms of poisoning in horses, cattle and
sheep are similar. Nausea, violent purgation which is sometimes
bloody, and general toxic symptoms are observed. In case of
Some Poisonous Plants in Florida 35
prolonged illness, muscular tremors, general weakness and emaci-
Prevention.-Livestock seldom eat the plant or beans when
sufficient desirable feed is provided.
Treatment.-No specific treatment for castor-bean poisoning
can be recommended.
Graceful Nightshade, Black Nightshade, Deadly Nightshade
Description. Nightshade (Solanum gracile Link.) is a ten-
der, low-growing plant with spreading or upright green stems
and numerous branches. It may persist through the winter in
protected places or grow all year in southern Florida. The al-
ternate leaves, one to four inches long, are borne on rather short
Fig. 15.-Nightshade-flowering shoot with fruit, flowers and berry.
36 Agricultural Experiment Stations
leaf-stalks that merge into the leaf-blade. The leaves are oblong,
oval, or narrow, pointed at both ends, with wavy or sometimes
slightly toothed margins. The flowers, borne at the leaf-axils in
stalked clusters, are white, star-shaped with five petals and a
yellow protruding center. The small berries, about 1/4 inch in dia-
meter, become purple or black when ripe. Each berry contains
several small, flat, yellowish seeds embedded in greenish pulp.
Habitat and Distribution.-Nightshade grows nearly every-
where except close to salt water. It prefers shady locations but is
also found in open sunny places, often among high weeds, along
fencerows, in old fields and gardens, and especially along the
edges of hammocks.
Toxicity.-The leaves and unripe berries contain a saponin-
like alkaloidal glucoside, solanin. It has a paralytic action on the
motor and respiratory centers of the brain. The greatest concen-
tration of alkaloid is contained in the unripe berries; the ripe
berries often are consumed by birds and humans without harm.
The green plant and unripe berries have been reported poison-
ous to all classes of livestock, including chickens.
The amount of alkaloid in the plant is said to vary with soil,
climatic and growth conditions.
Symptoms.-Weakness, stupor, staggering gait, extreme nerv-
ousness, staring eyes, dilated pupils and paralysis are symptoms
of nightshade poisoning in cattle, sheep and hogs. The progress
of the symptoms usually is rapid and poisoned animals often are
Prevention.-The plant normally is an annual growing from
the seed only, except in the southern counties; it should be re-
moved and destroyed before the berries form. Eradication by
this means is not difficult.
Treatment.-No treatment is known for nightshade poisoning.
Description.-Johnson grass (Sorghum halepense (L.) Pers.)
is a coarse, weedy perennial grass, two to five feet tall, with rough
scaly rhizomes or underground stems extending in all directions.
The flowering stems are erect, 1, to 1/ inch in diameter, light
\I ; Fig. 16.-Johnson grass
--rlo:wer cluster with leaf;
ii underground rhizome.
-iiderr ou d rhizome..
38 Agricultural Experiment Stations
green and often marked with dark red or brown diseased spots.
The leaves are long and narrow, usually less than 1 inch wide
and with a prominent, pale midrib. The flower cluster or panicle
is terminal at the top of the stem, 6 to 20 inches long and bears
numerous flowers and seeds. Each flower or spikelet is narrowly
ovate, nearly erect, slightly hairy or silky and furnished with a
hair-like awn about 1/2 inch long which is bent below the middle
to form a blunt angle. (Fig. 16.)
Habitat and Distribution.-Johnson grass is found in open
ground, cultivated fields, roadsides, around barns and farm yards
and in waste areas around rubbish piles. It occurs nearly all
over the state, but is most common in cultivated areas.
Toxicity.-Johnson grass is a cyanogenetic plant. It contains
a glucoside which yields hydrocyanic acid on hydrolosis. See dis-
cussion under sorghum.
Sorghum, Sorgho, Kafir, Dura, Milo, Feterita, Shallu, Kaoliang,
Broomcorn, Sudan Grass
Description.-Sorghum (Sorghum vulgare L.) and its varie-
ties compose a large group of coarse, annual grasses, with up-
right stems 2 to 15 feet in height having 7 to 18 joints. There
may be several lateral shoots at the base. The leaves, one at
each joint, are long, narrow, sharply toothed along the margin,
and have a prominent midrib, white, gray or yellow in color.
The flower cluster or seed head varies from 5 to 18 inches in
length (longer in broomcorn) and may be dense or open and have
the branches erect, spreading or drooping, but always in whorls.
The seeds and kernels of the various kinds of sorghum vary in
size, shape, and especially in color, being white, pink, yellow, buff,
brown or reddish brown. (Fig. 17.)
Habitat and Distribution.-Sorghum and its varieties are
seldom found except where they have been planted, although
spilled seeds may occasionally produce plants along lanes and
around farm buildings. They are widely planted in the northern
part of the state for syrup, grain for feeds, hay and ensilage.
Toxicity.-Although sorghum and its varieties are widely
grown as feed crops, they become toxic under the conditions de-
scribed below. They belong to a group known as cyanogenetic
plants. Such plants contain a glucoside from which prussic acid
cluster with leaf.
40 Agricultural Experiment Stations
or hydrocyanic acid is liberated. Hydrocyanic acid is one of the
most potent poisons known. The acid must be liberated from the
glucosidal combination before poisoning can result. Enzymes
which are present in the plant tissues free the hydrocyanic acid
from the remainder of the glucoside. The acid is absorbed and
carried by the blood stream to the body tissues where the action
of the oxidative enzymes is inhibited. The tissues fail to receive
oxygen. The process is one of internal asphyxiation.
A number of factors affect the amount of cyanogenetic glu-
coside found in the plant. The application of nitrogenous fertil-
izers has been known to increase it 20 times, particularly on
poorer soils. The amount of glucoside in the plant decreases as
it matures. Differences in cultural practices and climatic condi-
tions cause variation in glucosidal content. Second growth and
plants stunted by drouth or other unfavorable conditions are par-
Much of the hydrocyanic acid is set free when the cut plant is
dried slowly. Sorghum raised under drouth conditions is par-
tially dry when cut, dries quickly, and therefore is potentially
dangerous and should be fed with caution.
Cyanogenetic plants killed by frost often are dangerous for
a number of days. While this may appear to be true in some in-
stances, probably more important is the conditions under which
the plant is fed, as well as physical conditions in the stomach of
the animal to which it is fed.
Symptoms.-Lethal amounts of hydrocyanic acid cause death
almost instantaneously, with spasms and respiratory paralysis.
Smaller doses cause a short period of initial stimulation, as-
sociated with excitement and convulsions. Depression then oc-
curs. Respirations become deeper and accelerated, later to
become weak and irregular before finally ceasing. The pupils
are dilated. The eyes are prominent, glassy, staring and non-
sensitive to light. The nostrils and mouth usually are filled with
foam. Involuntary urination and defecation often occur.
Prevention.-The feeding of concentrates tends to prevent in
the rumen the liberation of hydrocyanic acid from sorghum
which may be eaten within approximately 24 hours thereafter.
Large amounts of dextrose also tend to reduce harmful results.
Drouth-injured sorghum can be utilized with safety if placed in
a silo, adding sufficient water to insure fermentation.
Some Poisonous Plants in Florida 41
Treatment.-Hydrocyanic acid poisoning progresses rapidly if
a fatal dose has been consumed. Treatment, if beneficial, must be
administered before respiratory paralysis begins to occur. So-
dium nitrite, sodium thiosulphate, or both in combination, as
well as methylene blue with calcium gluconate administered
intravenously are effective antidotes. Treatment should be given
promptly and preferably by a veterinarian.
Oriental Cocklebur, Clotbur, Cocklebur
Description. Cocklebur (Xanthium pungens Wallr.) is a
robust annual weed one to four feet tall with stout stems and
spreading branches. The leaves are alternate, long-stalked and
simple; the leaf-blades, 2 to 10 inches long, are nearly heart-
shaped or triangular, with toothed and sometimes lobed margins.
The whole plant feels rough to the touch and the stems are often
spotted with small dull red patches. Although the flowers are
greenish and inconspicuous, the fruits are very prominent. These
pods, about one inch or less long, are oblong, green or brown, cov-
ered with hooked prickles, and bear two longer, hard spines at
the end. Each bur contains two seeds, one of which germinates
the next season and the other may not grow until several years
late. Each seedling has two thick, fleshy, dark green seed-leaves
about one inch long. (Fig. 1.)
Habitat and Distribution.-Cockleburs occur most commonly
in old fields, but also in more recently cultivated soil, especially
in low areas. They also occur along ditches, streams and road-
sides. The weed is most common in the central, northern and
western areas of Florida.
Toxicity.-The germinating seeds and young seedlings con-
tain the highly poisonous glucoside, xanthostrumarin. Young
seedlings are extremely rich in this toxic principle and are dan-
gerous to all classes of livestock. At this stage of growth they
have two long, rather narrow, pointed leaves which appear en-
tirely different from the mature cocklebur leaf. Thus, they often
are not recognized. As the plant develops from this stage, it grad-
ually loses its toxicity. The mature plant has a bitter, disagree-
able taste and animals usually will not eat it.
There is some question as to whether the dormant seeds of
cocklebur are poisonous. They are covered with a spiny bur and
animals do not consume them readily. Occasionally, young pigs
42 Agricultural Experiment Stations
have been known to eat the seeds, which sometimes cause choking
and produce an inflammation in the stomach. However, exten-
sive losses in swine never have been attributed to eating cockle-
bur seeds. Considerable loss in the value of graded wool is re-
ported each year as a result of cockleburs becoming entangled in
the wool of sheep. Extensive irritation of the sheath of steers
and bulls occasionally occurs as the result of masses of cockleburs
becoming embedded in the hair in this area.
Cocklebur poisoning occurs in the early spring as a result of
animals, particularly hogs, eating young plants in the cotyledon
stage. The plants usually are found on low, wet land which has
recently dried. Under these conditions a large number of seeds
sprout over a short period of time. As a general rule these young
seedlings often constitute the only available green material for
grazing at thetime. In the early spring hogs usually are hungry
for green vegetation. The cocklebur seedlings are succulent and
apparently palatable, as hogs eat them with relish, even though
the animals are well fed otherwise.
One-quarter to 1/2 pound of the seedlings consumed over a
short interval will kill a 30- to 60-pound pig in 6 to 24 hours.
Smaller quantities consumed over a longer period of time often
result in cases of poisoning, although the animals may live for
four to five days after initial symptoms are shown. The seed-
lings are reported to be equally as toxic for sheep as for swine.
A dosage of twice this amount is required to poison calves. A
dosage of 20 grams, which represents about 30 seedlings, will kill
two-pound cockerels within 24 hours.
Symptoms.-The initial symptom of cocklebur poisoning in
pigs is depression, often accompanied by nausea and occasionally
vomiting. Affected animals become gaunt, weak and unable to
stand. Respiration is labored. The pulse is rapid and weak.
Affected animals unable to rise often paddle their legs in running
movements until too weak to do so. The progress of symptoms
depends in a large measure upon the amount of seedlings con-
sumed. When injury results from eating the seedlings in
amounts not large enough to produce death, several weeks are re-
quired for the animals to regain their normal condition.
Symptoms of cocklebur poisoning in sheep and cattle are
quite similar to those in hogs. However, vomiting does not oc-
cur, but trembling and quivering of the muscles often are noted.
Some Poisonous Plants in Florida 43
Prevention.-Cockleburs are difficult to eradicate, as some of
the seeds do not germinate for several years. In some areas it
may be practical to mow the weeds before the seed mature.
Pigs as well as sheep and calves should be confined in fields
which do not harbor cockleburs until the danger from young
seedlings is past.
Treatment.-The administration of milk, oils or fats is con-
sidered to have some beneficial effects in treating cocklebur
poisoning. However, when symptoms occur the major portion of
the toxic principle has been absorbed; the poison also acts quickly,
which reduces the benefits to be derived from treatment. Efforts
should be made to prevent animals from consuming the seedlings.
Atamasco-lily, Easter-lily, Rain-lily
Description.-Atamasco-lily (Zephyranthes atamasco Herb.)
is a low, herbaceous, perennial bulbous plant, commonly growing
in clumps. The bulb, buried one or two inches deep, is ovoid, one
inch or less in diameter, composed of layers (like an onion),
white inside but covered with a thin brown skin-like coat. The
leaves, which appear late in fall or early in spring, are harrow,
grass-like, 4 to 10 inches long and about 1/4 inch wide, erect or re-
clining, and bluish green in color. The flowers, appearing in early
spring, are borne erect on upright, slender stalks two to six inches
long, one on each stalk. The flower, two to three inches long, is
composed of six petal-like parts like a six-pointed star, the points
spreading or curling back, white or pinkish in color and with six
golden yellow stamens on short stalks near the center. The seed-
pods are three-angled, about 1/2 inch across and contain several
smooth, flat, black seeds. (Fig. 18.)
Habitat and Distribution.-Atamasco-lily or a close relative
grows nearly all over Florida. It is most common in flatwoods,
low grassy fields and in the northern areas on tussocks in swamps.
Related Species.-Z. treatiae S. Wats. has narrow leaves, 1/8
inch wide, and grows scattered in flatwoods, Z. simpsoni Chapm.,
growing in the southern areas, has flowers which do not open
wide, the floral parts remaining erect.
Toxicity.-Cases of poisoning have been observed in horses,
cattle and chickens. The bulb is the most poisonous part of the
plant. It has an extremely acrid taste. Approximately two
44 Agricultural Experiment Stations
rlily-two entire lants with flowers leaves and bulbs.
Fig. 18.---Zephyrlily--two entire plants, with flowers, leaves and bulbs.
Some Poisonous Plants in Florida 45
pounds of the fresh bulbs will prove fatal to a 300- to 400-pound
steer. Forty grams of bulbs is lethal to a mature chicken.
Symptoms.-The feces become soft in cattle and horses and
often streaked with bloody mucous. Staggering occurs within 48
hours after the plant has been consumed. The affected animal
collapses suddenly and usually dies without struggle.
Prevention.-Animals should not be allowed to graze infested
areas in the spring when there is not an abundance of desirable
Treatment.-No treatment can be recommended.
Other Poisonous Plants
Plants named in the following list occur throughout Florida
and are known to be poisonous under some conditions. While it
may be said that the first eight are perhaps more poisonous than
the remainder, results of eating them chiefly depend on amounts
eaten. Almost all will produce symptoms and death if a sufficient
quantity is consumed. Those marked are introduced or foreign
plants used in Florida for ornamental or other purposes.
\*Abrus precatorius L., jequirity rosary pea, crab-eye.
Crotalaria sagittalis L., arrow crotalaria.
"*Delphinium spp., hardy larkspurs.
Hydrangea arborescens L., smooth hydrangea.
*Hydrangea macrophylla DC, bigleaf hydrangea.
*Jatropha curcas L., barbados nut.
Kalmia latifolia L., mountain laurel kalmia.
"*Melilotus officinalis (L.) Lam., yellow sweet clover.
Aesculus pavia L., red buckeye.
"*Allamanda cathartica L., common allmanda.
Amianthemum muscaetoxicum (Walt.) A. Gray, crow
Apocynum cannabinum L., hemp dogbane.
"*Argemone mexicana L., mexican pricklepoppy.
Asclepias tuberosa L., butterfly milkweed.
Asclepias verticillata L., whorled milkweed.
"*Buxus sempervirens L., common box.
Cephalanthus occidentalis L., common buttonbush.
Cicuta curtissii C. & R. curtiss water hemlock.
46 Agricultural Experiment Stations
\*Colocasia esculenta Schott., elephants ear.
Euphorbia heterophylla L., painted euphorbia, wild poin-
Eapllr b;in maculata L., spotted euphorbia.
"*Glorioso superba L., glorylily.
Gossypium spp., cotton.
Helenium tenuifolium Nutt., bitterweed.
Lachnanthes tinctoria Ellis, blood redroot, paintroot.
Leucothoe catesbaei (Walt.) Gray, drooping leucothoe.
Leucothoe racemosa (L.) Gray, sweetbells leucothoe.
Lobelia cardinalis L., cardinal-flower.
Lupinus perennis L., sundial lupine.
Lyonia mariana (L.) D. Don., staggerbush lyonia.
Lyonia ligustrina (L.) DC., he-huckleberry.
"*Nicotiana glauca R. Grah., tree tobacco.
Oxypolis filiformis (Walt.) Britton, leafless cowbane.
Phaseolus lunatus L., lima bean.
Phytolacca rigida Small, southern pokeweed.
Quercus spp., oaks
Ranunculus spp., buttercups.
Sambucus simpsoni Rehder, Florida elder.
Solanum carolinese L., carolina horse-nettle.
*Solanum tuberosum L., potato
Tephrosia virginiana (L.) Pers., Virginia tephrosia.
"*Thevetia nereifolia Juss., luckynut thevetia, yellow oleander.
Triglochin striata R. & P., ridged podgrass, arrow grass.
Plant Causing Mechanical Injury
Hairy indigo (Indigofera hirsuta L.) is not a poisonous plant.
In some instances when cattle graze hairy indigo the skin of the
legs from the hoof as far up as the knees becomes swollen, scabby,
cracked and often bleeding. Whether this condition is due to a
mechanical injury following continual wetting of the skin of the
legs, as occurs when well grown hairy indigo is grazed daily, or
due to other factors or combination of factors is not known. In
such instances, however, affected animals should be confined to
Some Poisonous Plants in Florida 47
keep the skin of the legs dry and only allowed on short pasture
after it is dry from dew or rain. The affected areas should be
watched closely for screwworm infestations. Sulfa ointments
applied to the areas facilitate healing. (Fig 19.)
Fig. 19.-Hairy indigo-flowering shoot with fruit cluster.
The authors wish to thank Miss Esther Coogle, Staff Artist, College of
Agriculture, for preparing the illustrations used in this bulletin. All of
them were made from living specimens.