苍耳 cang er

Xanthium americanum Walter; X. chasei Fernald; X. chinense Miller; X. curvescens Millspaugh & Sherff; X. cylindricum Millspaugh & Sherff; X. echinatum Murray; X. echinellum Greene ex Rydberg; X. globosum C. Shull; X. inaequilaterum Candolle; X. indicum J. Koenig ex Roxburgh var. inaequilaterum (Candolle) Miquel; X. inflexum Mackenzie & Bush; X. italicum Moretti; X. japonicum Widder; X. mongolicum Kitagawa; X. orientale Linnaeus; X. oviforme Wallroth; X. pensylvanicum Wallroth; X. sibiricum Patrin ex Widder; X. sibiricum var. jingyuanense H. G. Hou & Y. T. Lu; X. sibiricum var. subinerme Widder; X. speciosum Kearney; X. strumarium var. canadense (Miller) Torrey & A. Gray; X. strumarium var. glabratum (Candolle) Cronquist; X. strumarium var. japonicum (Widder) H. Hara; X. strumarium subsp. sibiricum (Patrin ex Widder) Greuter; X. varians Greene; X. wootonii Cockerell.

Herbs, annual, 20-120 cm; nodal spines absent. Petiole 3.5-10 cm, not winged; median cauline leaves ovate-deltate, 9-25 cm, papery, densely scabrid on both surfaces, base shallowly cordate to broadly cuneate, margin irregularly dentate, often obsoletely 3-lobed, apex acute. Capitula monoecious. Male capitula in terminal umbels; phyllaries 1-seriate, oblong-lanceolate, ca. 2.2 mm; outer paleae oblong-lanceolate, inner paleae lanceolate, ca. 2.2 mm; corolla white, tubular, ca. 2.5 mm, 5-dentate. Female capitula axillary; phyllaries 1-seriate, oblong-lanceolate, ca. 3 mm, inner bracts connate with outer paleae. Burs sessile, oblong, ellipsoid, or ovoid, 10-18 × 6-12 mm, densely puberulent, 2-beaked. Fl. Jul-Aug, fr. Sep-Oct. 2n = 36.

Damp or seasonally wet often alkaline soils, wastelands, margins of agriculture, common weed. Anhui, Fujian, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [a pantropical weed, known to be widely distributed in both Old and New Worlds, but most probably originating in the New World].