POISONOUS AND INJURIOUS PLANTS 87 
DistripuTion AND Hasrrat.—Sorghum, sudangrass, and related 
forms are seldom found except where they have been planted, although 
spilled seeds may occasionally produce plants along lanes and fences, 
and around the edges of fields and farm buildings. Sorghums and 
sudangrasses are grown in the Virgin Islands primarily for temporary 
pasture, soilage, and ensilage. Escape plants may be found in aban- 
doned fields, waste grounds, and around farm buildings. Sorghums, 
in general, are drought tolerant. This characteristic, coupled with 
their copious seed production and general competitiveness, makes the 
plants valuable for forage, although they constitute a constant danger 
to livestock. Sudangrasses have been grown successfully in the Virgin 
Islands on comparatively shallow, infertile soils in low rainfall belts. 
Toxiciry AND Symproms.—Sorghums grown under adverse condi- 
tions often contain the cyanogenetic glucoside dhurrin (25, 56). Dhur- 
rin is broken down in the stomach of animals to release a very deadly 
material named hydrocyanic acid which ties up the hemoglobin, so the 
blood cannot carry enough oxygen. Very small quantities of the ma- 
terial produce poisoning. Of our farm animals, cattle are most sus- 
ceptible, horses and sheep less so, while hogs are seldom affected (79). 
Lethal amounts cause death to occur suddenly from respiratory par- 
alysis. Smaller doses cause animals to become excited at first and 
then extremely depressed. Respirations are deep and accelerated at 
first but become weak and irregular. The eyes become dilated and 
nak the nostrils and mouth are usually filled with foam. Bloating, 
requent urination, and defecation may occur. The breath has an 
almond odor. 
MANAGEMENT AND Controt.—Although sorghums and sudangrasses 
are widely grown as feed crops, they may become toxic under certain 
conditions, among which are the dry periods that occur repeatedly 
at unpredictable intervals in the Virgin Islands. They act as weak 
perennials under local conditions, producing several ratoon crops 
from one planting, which may be beneficial, even though it is rather 
hazardous to graze or otherwise use ratoon crops produced during 
extremely dry periods. Plants that have been stunted by drought 
or other unfavorable conditions should never be fed to livestock. 
Euphorbiaceae, or Spurge, Family 
Thevetia peruviana (Pers.) K. Schum. (fig. 48) 
Luckynut 
Descrietion.—This many-branched shrub, or small tree, is 10 to 
20 feet high; its crown may be sprangly or dense. The bark on old 
stems is hght gray and slightly fissured, while that on young twigs is 
green and smooth. The short-stemmed leaves are tapered to sharp 
points at both ends, 3 to 6 inches long, and less than 14 inch wide, 
with a strong prominent midvein from which smaller side veins 
extend; they are dark green and shiny above, dull beneath, and occur 
alternately or in a whorled arrangement along the stem near the 
tips of the branches. The bright yellow flowers are produced in small 
clusters near the tips of the twigs. Each funnelform flower is 2 to 3 
inches long and extends out into 5 short, dull-pointed lobes; they are 
pretty but not very fragrant. The fruits are borne on long, slender 
stems which are attached to the middle of one side, making them wider 
than long. The fruits, which contain 2 seeds, are somewhat triangular 
