Jatropha curcas seeds mature in November.
Shrubs or treelets, 2-5 m tall, with watery latex; bark smooth; branches glaucous-gray, glabrous, sparsely lenticellate, pith larger. Stipules small; petioles 6-18 cm; leaf blade rotund to ovate, 7-18 × 6-16 cm, papery, nitid green and glabrous adaxially, gray-green and along nerves puberulent to glabrous abaxially, base cordate, apex acute; palmate veins 5-7. Inflorescences axillary, 6-10 cm; bracts lanceolate, 4-8 mm. Male flowers: sepals 5, ca. 4 mm, connate at base; petals oblong, green-yellow, ca. 6 mm, connate to middle, hairy inside; disk glands 5, nearly terete; stamens 10; outer 5 filaments free, inner filaments connate in lower part. Female flowers: pedicels elongate; sepals free, ca. 6 mm; petals and disk glands as in male; ovary 3-locular, glabrous; styles bifid at apex. Capsules ellipsoidal or globose, 2.5-3 cm, yellow. Seeds ellipsoidal, 1.5-2 cm, black. Fl. Sep-Oct, fr. Oct-Dec.
- Cultivated for medicine. Fujian, Guangdong, Guangxi, Hainan, Sichuan, Taiwan, Yunnan [native to tropical America; widely introduced].
Jatropha curcas seeds are the source of curcas oil, a very powerful purgative, also used for making candles and soap, for lighting, and as a lubricant. There is interest in the oil as a biofuel crop for areas too dry for normal crops. The bark is used as medicine for lepriasis (leprosy), itchy skin, eczema, chronic ulcers, etc.