[Greek iatros, physician, and trophe, food, alluding to use of J. curcas as purgative] [Greek iatros, physician, and trophe, food, alluding to use of J. curcas as purgative]

Bijan Dehgan

Herbs, subshrubs, shrubs, or trees, perennial, monoecious or dioecious [gynodioecious]; hairs unbranched, sometimes glandular, or absent; latex colorless, cloudy-whitish, yellow, or red. Leaves deciduous or persistent, alternate but sometimes appearing fascicled, simple; stipules absent or present, persistent or deciduous; petiole absent or present, glands absent at apex, sometimes stipitate-glandular along length; blade unlobed or palmately lobed, margins entire, serrate, or dentate, laminar glands absent; venation pinnate or palmate. Inflorescences unisexual or bisexual (pistillate flowers central, staminate lateral), axillary or terminal, cymes or fascicles, or flowers solitary; glands subtending each bract 0. Pedicels present. Staminate flowers: sepals 5, imbricate, distinct or connate to 1/2 length; petals 5, distinct or connate basally to most of length, white, greenish yellow, pink, red, or purple [yellow, yellow-brown, orange, or 2-colored]; nectary extrastaminal, annular and 5-lobed or of 5 glands; stamens [6–]8 or 10 in 1–2 whorls, distinct or connate basally to most of length; pistillode absent. Pistillate flowers: sepals 5, imbricate, distinct or connate to 1/2 length; petals 5, distinct or connate basally to most of length, white, greenish yellow, pink, red, or purple [yellow, yellow-brown, orange, or 2-colored]; nectary annular and 5-lobed or 5 glands; staminodes sometimes present; pistil 1–3-carpellate; styles (1–)3, distinct or connate basally to most of length [absent], 2-fid. Fruits capsules, ± fleshy, sometimes tardily dehiscent. Seeds ellipsoid to globose; caruncle present (sometimes rudimentary) or absent. x = 11.

Species ca. 190 (10 in the flora): s United States, Mexico, West Indies, Central America, South America, s Asia (India), Africa; introduced elsewhere in Asia, Pacific Islands, Australia; tropical and subtropical regions.

Some species of Jatropha are cultivated as ornamentals throughout the tropical and subtropical regions of the world, notably J. integerrima, J. multifida, and J. podagrica Hooker. These and J. curcas Linnaeus and J. gossypiifolia Linnaeus have escaped from cultivation in subtropical regions. Jatropha curcas (physic nut), which probably originated in Central America, is now pantropical and is extensively cultivated for production of biodiesel from its seeds, which are also eaten as roasted nuts and used as a purgative and for other medicinal purposes. More than 50 New World species are known from cultivation in the United States, either as ornamentals or for medicinal purposes, many of which are being studied. Some African species are in cultivation, primarily by collectors of succulent plants.

SELECTED REFERENCES Dehgan, B. 201. Jatropha. In: Organization for Flora Neotropica. 1968+. Flora Neotropica. 110+ nos. New York. No. 110. Dehgan, B. and B. Schutzman. 1994. Contributions toward a monograph of neotropical Jatropha: Phenetic and phylogenetic analysis. Ann. Missouri Bot. Gard. 81: 349–367. Dehgan, B. and G. L. Webster. 1979. Morphology and infrageneric relationships of the genus Jatropha (Euphorbiaceae). Univ. Calif. Publ. Bot. 74: 1–73. McVaugh, R. 1945. The genus Jatropha in America: Principal intergeneric groups. Bull. Torrey Bot. Club 72: 271–294.