Description from Flora of China
Trees or shrubs, rarely subshrubs, monoecious or more rarely dioecious; latex clear or reddish, often scanty or apparently absent; indumentum of stellate hairs and/or peltate scales. Leaves alternate, rarely opposite or nearly verticillate; stipules present or absent; petiole with or without apical paired glands; leaf blade simple, margin entire or denticulate, often with glands; venation pinnate or palmate. Inflorescences terminal or axillary, racemelike thyrses, often with proximal solitary female flowers and distal male flowers, often in clusters. Male flowers: sepals mostly 5, imbricate to valvate, free; petals 5, smaller or nearly equal to sepals; disk glandular, usually 5, and opposite sepals; stamens 10-20; filaments free, inflexed in bud; anthers muticous; pistillode absent. Female flowers: sepals 5, often narrower than in male, imbricate to reduplicate-valvate, persistent, sometimes accrescent; petals 5, smaller than in male, mostly reduced or obsolete; disk annular or dissected, receptacle often villous; ovary 3-locular; ovules 1 per locule; styles 3, longer and slender, free or nearly so, once to several times bifid. Fruit a capsule dehiscing into 3 2-valved cocci, more rarely ± indehiscent and fleshy, drupelike or berrylike. Seeds usually smooth, carunculate; testa crustaceous; endosperm copious, fleshy; cotyledon broad and flattened.
Many species are used medicinally. Several are extremely toxic. Croton moonii Thwaites (瘤果巴豆 liu guo ba dou), native to Sri Lanka, is cultivated for medicine in S Guangdong.
Nearly 1300 species: tropics and subtropics of the world, most numerous in the neotropics; 23 species (15 endemic) in China.
(Authors: Li Bingtao (李秉滔 Li Ping-tao); Hans-Joachim Esser)