This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Monoecious or rarely dioecious perennial stinging bristly herbs, or shrubs, with entire, lobed or divided petioled leaves, the flowers in cymes. Flowers apetalous. Staminate flowers on the upper parts of the cymes, with a corolla-like 5-lobed calyx, the stamens usually numerous (10 or more) and in several series, their filaments mostly united at the base. Pistillate flowers in the lower forks of the cymes; ovary mostly 3-celled and 3-ovuled; styles united at the base; capsule ovoid or subglobose, easily separating into 2-valved carpels; seeds ovoid or obovoid; embryo straight; endosperm fleshy. [Greek, stinging spine.]
About 20 species, widely distributed in warm and tropical America. Besides the following another occurs in the Southern States. Type species: Cnidoscolus hamosus Pohl.
Jatropha stimulosa Michx. Fl. Bor. Am. 2: 216. 1803.
Jatropha urens var. stimulosa Muell. Arg. in DC. Prodr. 15: Part. 2, 1101. 1862.
Perennial by a stout root, herbaceous, bright green, armed with stinging hairs. Stem rather slender, erect, simple or branched, 4'-3 1/2° tall; leaves nearly orbicular in outline, 2 1/2'-12' broad, truncate or cordate at the base, deeply 3-5-lobed, the lobes entire, toothed or pinna-tifid; calyx of the staminate flowers salver-form, white or pink, 10"-20" broad; capsule oblong, 5"-8" long, papillose, wrinkled; seeds oblong-obovoid, 5"-6" long, smooth, mottled.