+ Central Science
Nematology (Botany) Circular No. 30 Fla. Dept of Agric.Libr4fynsumer Ser
August 1977 Division of Plant Indust
MAR 26 1987
Physic nut, Jatropha curcas
University of Florida
K. R. Langdon
The physic nut, Jatropha curcas L. (other common names: Barbadosnut, purge
nut, curcas bean), a native of tropical America, is frequently grown in tropical
and subtropical areas throughout the world, including South Florida, as an orna-
mental and occasionally for medicinal purposes. It is unfortunately called by
some people pistachio or cashew. The true pistachio (Pistacia vera L.) and ca-
shew (Anacardium occidentale L.) are good, edible nuts of the family Anacardia-
ceae. The physic nut is in the family Euphorbiaceae and is unrelated to the true
pistachio or cashew, but rather to the castor bean (Ricinus communis L.). Physic
nuts have a pleasant taste similar to sweet almonds, giving no indication of their
irritant properties, and tempting persons, especially children, to eat more.
The physic nut is typical of many members of Euphorbiaceae, having a caustic,
milky sap and toxic seed. There apparently are variations in the toxicity of the
seeds, some varieties considered toxic and others considered harmless. The toxic
and harmless varieties can not be distinguished visually. Some people who have
eaten the supposedly harmless seeds have developed mouth sores.
DESCRIPTION: Jatropha curcas (fig. 1) is an annual shrub or short-lived
tree up to about 15 ft (5 m) tall. Stems thick, green, glabrous, mostly herba-
* ceous or somewhat succulent, becoming woody at the base. Leaves alternate, long
petioled, palmately veined, cordate
to truncate at the base, about 6 in.
(1.5 dm) wide, margin irregular or
with 3-5 shallow lobes, points acute
to obtuse. Flowers small, yellow,
unisexual, in clusters in leaf axils,
mostly hidden in foliage. Fruit an
ovoid, 3-locular capsule, at first
green and fleshy, becoming brownish
or almost black and dry at maturity,
containing up to 3 black seeds about
3/4 in. (20 mm) long.
TOXICITY: The seeds contain 25-
53% of a yellow fixed oil knownvar-
iously as Helloil, Pinhoenoil,Oleum
infernale, and Oleum ricini majors.
This oil is a more potent purgative
than castor oil, but less than cro-
ton oil. The purgative dose is 0.3-
0.6 ml. The seeds also contain a
S' phytotoxin, curcin, which is similar
to but not identical with ricin
from castor bean. Roasting is report-
ed by some to detoxify the nuts, al-
S Fig. 1. Jatropha curcas (after West, 1960) though a number of people have been
Contribution No. 172, Bureau of Nematology, P.O. Box 1269, Gainesville, FL 32602
poisoned to varying degrees from eating the roasted nuts. In addition to the
above products, the seeds also contain 2 phytosterols, a phytosterolin, and some
resinous matter which produces nausea, purging, and griping. In some instances
consumption of as few as 3 seeds has produced toxic symptoms. In others consump-
tion of as magg as 50 seeds produced relatively mild symptoms. Human deaths from
poisoning by this plant apparently have not been reported, though animal deaths
Symptoms and lesions are similar to those in poisoning by castor bean and
result primarily from severe gastroenteritis. A burning sensation in the throat,
followed by vomiting, diarrhea, abdominal pain, and associated symptoms have been
reported. Depression and collapse may occur, especially in children. The latex
of all parts of the plant is acrid, irritating, and toxic. The leaf isa drastic
purgative. Some varieties also possess stinging hairs.
USES: Whole seeds or the expressed oil have been used medicinally as a pur-
gative. These are rarely used now, being replaced by castor oil, a somewhat milder
and much safer material. Certain African tribes have used the seeds as an abor-
tifacient. The oil has been used for illuminating purposes, soap making, candle
making, and adulteration of olive oil. It is used as a lubricant because of its
low acidity. The nuts strung on grass and dried are used for illumination. The
oil has been used as a skin rub, and the seed used as an anthelmintic and skin
Other parts of the plant are also used. The leaf juice is used in India and
Africa for wound dressing and the latex as a hemostatic. The pounded leaf is used
as a fly repellent from horses' eyes. A leaf decoction is diuretic. The latex
is applied topically to wasp and bee stings. The root bark is used as an irritant
for rheumatism and the seed for dropsy, gout, paralysis, and skin disease. The
bark is used as a fish poison in the Philippines. The plant has been used to make
an arrow poison and as an ingredient in preparing poison maize as a bait for
guinea-fowl. Nuts ground and mixed with palm oil serve as rat poison.
Regardless of the reported edibility of the seeds of some plants, their good
taste, themisapplied common names, pistachio or cashew, or any other factors, it
is dangerous to eat seeds of even the supposedly harmless varieties.
Arnold, H. L. 1968. Poisonous plants of Hawaii. Charles E. Tuttle Co., Rutland,
Vermont. 71 p.
Kingsbury, J. M. 1964. Poisonous plants of the United States and Canada.
Prentice-Hall, Engelwood Cliffs, New Jersey. 626 p.
Morton, Julia F. 1971. Plants poisonous to people. Hurricane House, Miami.
Watt, J. M., and Marie Gerdina Breyer-Brandwijk. 1962. The medicinal and poison-
ous plants of southern and eastern Africa. E. & S. Livingstone, London.
West, E. 1960. Poisonous plants around the home. Florida Agriculture Extension
Service Bull. 175. 38 p.