POISONOUS AND INJURIOUS PLANTS 43 
pointed lobes along the margins. The large, white, trumpet-shaped 
flowers are borne singly in the leaf axils on short, stout stems; they 
are 6 to 8 inches long and 2 to 4 inches across the top. The base of 
the flower is surrounded by a funnel-shaped, leaflike structure. The 
erect, egg-shaped fruits, borne on stout stems, are green when young 
but become dry, hard, and pale tan at maturity. They are covered 
with hard, sharp prickles; the lower prickles are usually shorter than 
the upper ones. The mature, dry fruit, usually 2 inches long, splits 
into 4 sections and releases many small, black, shiny seeds. The seeds 
of jimsonweed are scattered by wind and water. This fast-growing 
weed is propagated by seeds that germinate at the onset of the wet 
season and produce plants that blossom and mature fruits during the 
ensuing dry season. The plants die after producing a seed crop. The 
plant color, odor, lack of hairs, and leaf shape make jimsonweed 
easily distinguishable from pricklybur. 
DistristTION AND Hasirat.—Jimsonweed occurs throughout the 
Virgin Islands, but is rather scarce on St. Croix. It is commonly 
found in waste grounds around house sites. It occurs spontaneously 
in pastures, cultivated fields, along stream and ditchbanks and road- 
sides, in refuse heaps, fence rows and feeding lots, and around cattle 
dips. It grows best in full sun but is shade tolerant. The plants can 
grow in dry areas, but they are usually larger when grown on fertile 
soils in the higher rainfall belts. The plants are most conspicuous 
when in flower and fruit. Rainfall appears to influence its distri- 
bution more than does soil type, as is the case with many other plants 
in the Tropics. Jimsonweed grows singly or more commonly in small 
patches; seldom in thick stands covering entire fields. 
Toxiciry aND Symptoms.—Jimsonweed contains three very poison- 
ous alkaloids—hyoscyamine, atropine, and scopolamine (6/7). All 
parts of the plant are poisonous, but the seeds are particularly danger- 
ous. One pound of the green plant is sufficient to kill a cow. How- 
ever, because of its strong odor and unpleasant taste, animals rarely 
eat enough of the plant to be poisoned. Children are sometimes pol- 
soned by chewing the flowers. Of farm animals, cattle most fre- 
quently are poisoned. Rare cases of hogs being poisoned have been 
reported (28). In cattle, rapid pulse and respiration and either 
frequent urination or retention of urine are common symptoms. 
Diarrhea, dilation of the pupils of the eyes, and stiffness occur. As 
death nears, respiration becomes slow, weak, and irregular. Poisoned 
hogs frequently go into a state of convulsive twitching. 
MANAGEMENT AND Controt.—The plant is a more-or-less permanent 
pest due to its copious production of seeds that remain viable in the 
soil for long periods. Probably because of its disagreeable odor and 
strong taste, this plant is seldom eaten by browsing animals and is 
not usually regarded as being dangerous to farm livestock. But 
livestock will feed on the plant when starving or confined to small 
areas, and it is a potential danger to livestock. Care should be taken 
not to include this weed in hay or silage. Getting rid of the plants 
by cutting, pulling, or grubbing them out before they mature seed is 
practical. Ordinary cultivation practices kill young plants. Use of 
commercial selective herbicides is an effective chemical control measure. 
