16. Ricinus L., Sp. Pl. 1007. 1753. Gen. Pl., ed. 5: 437. 1754; Muell. Arg. in DC., Prodr. 15(2): 1016. 1866; Benth. & Hook. f., Gen. Pl. 3(1): 321. 1880; Hook. f., Fl. Brit. Ind. 5: 457. 1887; Pax in Engl., Pflanzenreich 4. 147. 11: 119. 1919; Shishkin in Fl. U.R.S.S. 14: 300. 1949; Rech. f. & Schiman- Czeika in Fl. Iranica 6: 8. 1964; Stewart, Ann. Cat. Vasc. P1. W. Pak. & Kashm. 456. 1972.
A. RADCLIFFE-SMITH
A large monoecious glabrous annual or perennial herb. Leaves alternate, petiolate, stipulate, peltate, palmately-lobed, the lobes glandular-serrate, penninerved. Petioles glandular at apex and base. Stipule united to form a caducous sheath. Inflorescences paniculate, subterminal or leaf-opposed, ♂ in the lower half and ♀ in the upper or else all ♀; bracts membranous, soon caducous. Male flowers: pedicels articulate, bibracteolate; buds globose, closed, later splitting into 3-5 valvate lobes; petals 0; disc 0; stamens up to 1000 with the filaments variously united, anthers basifixed, the cells globose, longitudinally dehiscent; pistillode 0. Female flowers; pedicels extending in fruit; buds conical; sepals 5, valvate, soon caducous; petals 0; disc 0; ovary 3-celled, with 1 ovule per cell, echinate or smooth; styles 3, ± free, bipartite, papillose-plumose, dark red. Fruit trilobate, echinate or smooth, dehiscing into 3 bivalved cocci. Seeds dorsiventrally compressed-ovoid, smooth, carunculate, testa crustaceous, albumen fleshy; cotyledons broad, flat.
A monotypic genus originally native to NE Tropical Africa, but now widely cultivated throughout the tropics, subtropics and warm temperate regions, and often escaping and becoming naturalized.