POISONOUS AND INJURIOUS PLANTS ao) 
Description.—This fast-growing, spreading tree with smooth gray 
bark and thick twigs is 20 to 40 feet high. Like many other plants 
of its family, it has milky sap. Its horizontal branches form a sym- 
metrical crown. The young twigs, branches, flowering stems, and 
flowerbuds are densely covered with short, straight, whitish hairs. 
The large, dark-green leaves, borne alternately on long, stout stems, 
are broadly ovate. The thin leaf blades are about 6 inches wide and 
6 to 8 inches long: they are smooth on both surfaces. The flowers, 
about 14 inch in diameter, are borne in branched clusters at the tips 
of the twigs. Both male and female flowers occur in the same flower 
cluster. The petals, about 14 inch long, are hairy on the outside and 
vary in color from white through different shades of pink. The 2- 
to 5-celled, spherical fruits are produced on long drooping stems. 
They are hairy and green when young, and become hard and almost 
black at maturity. The fruits are 2 to 3 inches in diameter, and 
contain 3 to 7 large egg-shaped, hard, brown seeds; each seed is about 
linch long. The trees are deciduous when grown in higher latitudes, 
but they rarely shed all their leaves in this climate. The trees blossom 
during the early spring and mature their fruits during the fall. Tung 
trees are reproduced by seeds. 
DisTRIBUTION AND Haprirat.—The tung tree is a native of China. 
It was introduced into the Virgin Islands in 1923 (42). Subsequently, 
an experimental planting of considerable size was made at Anna’s 
Hope, St. Croix, and a smaller planting was made at Estate Orange- 
grove. 
Toxiciry anp Symproms.—The leaves, sap, fruit, and commercial 
tungoil contain a saponin, which is known to be toxic to cattle, horses, 
chickens, and humans (6/7). Under normal conditions animals never 
browse the trees, but they relish leaves from broken or discarded 
branches. In cattle, acute poisoning results in death in 3 to 4 days, 
while chronically poisoned animals may linger for 18 to 24 days before 
dying. Two pounds of leaves will kill a 500-pound steer. Common 
symptoms are hemorrhagic diarrhea, lack of appetite, listlessness, 
and depression. Chronic poisoning may produce labored breathing, 
salivation, and cracking of the skin of the muzzle. When taken inter- 
nally, tungoil has a severe purgative and emetic effect (20). Humans 
are frequently poisoned by eating the fruits; a severe gastroenteritis 
develops, followed by mild or severe purging. 
MANAGEMENT AND Controu.—The possibility of livestock poisoning 
from the tungoil tree is negligible because of its restricted distribu- 
tion. Although most plantings of Tung in the continental United 
States are made for commercial oil production, the trees are occa- 
sionally planted for shade and ornament. Denying livestock access 
to the trees, both young and mature, is recommended because the 
foilage, sap, and fruits are all poisonous. 
Anacardiaceae, or Sumac, Family 
Anacardium occidentale L. (fig. 3) 
Cashew 
Description.—This tree is 20 to 40 feet high. Its spreading limbs 
form a symmetrical crown, especially when it grows singly in the 
open. The rather smooth bark of the trunk is gray; it is lighter on 
young twigs. The alternate, entire, roundish leaves, which are 8 to 
