Monographs Details: Jatropha stephani J.Jiménez Ram. & Mart.Gord.
Authority: Dehgan, Bijan. 2012. . Fl. Neotrop. Monogr. 110: 1--274. (Published by NYBG Press)
Synonyms:Jatropha martinezii E.J.Lott & Dehgan
Description:Species Description - Shrubs or trees, 2-10 m tall, dioecious. Stems: reddish, younger branches and growing tips minutely white-puberulent, older branches glabrescent, bark yellow, exfoliating; latex clear to cloudy and yellowish, drying red. Leaves: deciduous to semievergreen, stipules absent; petioles 3-3.5 cm long and 1.4-2.2 mm in diam., villous with white or red hairs; blades ovate to broadly ovate, unlobed, 6-14 x 3-8 cm, coriaceous, base broadly acute, margins entire when mature but younger blades often beset with round, sessile glands, apex acute, veins pinnate, with a strong central vein and 7-9 pairs of secondary veins, glabrous above, greenish white, densely puberulent beneath. Inflorescences: subterminal or lateral, staminate many-flowered cymes with peduncles 1.5-6 cm, pistillate solitary or few and nearly sessile; bracts ovate to triangular, 5-1 x 0.3 mm, acute, pubescent, often red-villous along margins; pedicels 5-7 mm long. Staminate flowers: sepals elliptic to ovate, 0.4-0.6 x 0-3 0.4 mm, distinct, margins ciliate, not glandular, apex acute, densely pilose on both surfaces; corollas narrowly urceolate, rose-pink, petals 10-13 x 4-6 mm connate to ca. 2/3 of length, apex round, strongly reflexed, puberulent on both surfaces; stamens 10, monadelphous-biseriate (5 + 5 or rarely 4 + 6); filaments of outer series 0.6-0.8 mm long and those of inner series 0.7-0.9 mm and connate to ½ of length. Pistillate flowers: like staminate but sepals foliaceous, markedly unequal, 0.7-1.5 x 3-7 mm, sometimes ± imbricate; corollas broadly urceolate, petals 10-15 x 7-9 mm, connate to ca. 2/3 of length, strongly reflexed; carpels 3, styles 1-2 mm long, ovary glabrous. Capsules: nearly spherical 2-3 x 2.3-3 cm, distinctly 3-lobed, glabrous, tardily dehiscent. Seeds: light brown with darker brown, longitudinal streaks, ellipsoid, ca. 2 x 0.9 cm in diam., caruncle vestigial.

Discussion:Local name. Piñoncillo.Jatropha stephani is closely related to the J. standleyi group and, in fact, may be endemic to the Balsas River basin. The other cited specimens may be aberrant specimens of J. standleyi. It is difficult to be more specific in assigning the specimens without flowers.
Distribution:Guerrero Mexico North America| Michoacán Mexico North America| Oaxaca Mexico North America|