乌桕 wu jiu

Croton sebifer Linnaeus, Sp. Pl. 2: 1004. 1753 ["sebiferum"]; Excoecaria sebifera (Linnaeus) Müller Argoviensis; Sapium chihsinianum S. K. Lee; S. discolor (Champion ex Bentham) Müller Argoviensis var. wenhsienense S. B. Ho; S. pleiocarpum Y. C. Tseng; S. sebiferum (Linnaeus) Roxburgh; S. sebiferum var. cordatum S. Y. Wang; S. sebiferum var. dabeshense B. C. Ding & T. B. Chao; S. sebiferum var. multiracemosum B. C. Ding & T. B. Chao; S. sebiferum var. pendulum B. C. Ding & T. B. Chao; Triadica sinensis Loureiro.

Trees to 15 m tall, monoecious, glabrous; bark dark green, with longitudinal stripes, pale brownish when older; branchlets spreading, lenticellate. Leaves alternate; stipules 1-1.5 mm; petiole 2.5-6 cm, 2-glandular at apex; leaf blade rhomboid, rhomboid-ovate, broadly ovate, or rarely rhomboid-obovate, 3-13 × 3-9 cm, papery, base broadly rounded, truncate, or sometimes shallowly cordate, margin entire, apex acutely acuminate; midrib slightly elevated on both surfaces, lateral veins 6-12. Flowers yellowish green in terminal 3-35 cm racemes, female in lower part, male in upper part or male throughout. Male flowers 10-15 per bract; bracts broadly ovate, 1.5-2 × 1.5-2 mm, basal glands nearly reniform; pedicels slender, 1-4 mm; bracteoles 3, unequal, margins lacerate; calyx cup-shaped, shallowly 3-lobed, lobes obtuse, irregularly serrulate; stamens 2 or 3, exceeding calyx; filaments free, nearly as long as globose anthers. Female flowers 1 per bract, sometimes with several additional male flowers; bracts 3-partite, lobes acuminate, glands as in male; pedicels stout, 2-5 mm; bracteoles as in male flowers; calyx 3-partite, lobes ovate or ovate-lanceolate; ovary ovoid-globose, smooth, 3-celled; styles 3, connate at base; stigma revolute. Infructescences up to 28 cm; capsules subglobose to pyriform-globose, black when mature, 11-13 mm in diam., 3-seeded; cocci deciduous; columella persistent. Seeds oblate, ca. 8 × 6-7 mm, black, covered with white, waxy aril. Fl. Apr-Aug, fr. Aug-Dec. 2n = 44.

Wilds of the Huang He valley, forests on limestone, widely cultivated; below 100 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hubei, Jiangxi, Jiangsu, Shaanxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [Japan, Vietnam; cultivated in Africa, America, Europe, India].

The pressed seeds of Triadica sebifera are a source of fat, used for candles and soap. The bark and the seed oil contain a poisonous alkaloid. Its roots are used as a medicine to detoxify snakebites. The leaves are used in making a dark dye.