豨莶 xi xian

Sigesbeckia brachiata Roxburgh; S. caspia Fischer & C. A. Meyer; S. esquirolii H. Léveillé & Vaniot; S. gracilis Candolle; S. humilis Koidzumi; S. iberica Willdenow; S. microcephala Candolle; S. orientalis var. caspia (Fischer & C. A. Meyer) Grossheim.

Annuals. Stems erect, simple or dichotomously branched, branches opposite, obtusely angulate, 30-75(-100) cm tall, ± crisp pubescent to densely pubescent, especially in upper part. Leaves ovate-triangular, ovate, or oblong-ovate, finely and appressed pilose, especially abaxially, sometimes with sparse small glands and hairs, base cuneate or rounded to subcordate, margin largely and usually unequally toothed to sinuate-dentate, sometimes resembling reduced leaves of sunflower, apex acute or acuminate. Capitula small, ca. 5 mm wide; outer phyllaries with dense stipitate-glandular hairs, oblong-obovate or linear-spatulate, considerably longer than inner, sometimes broader and with small number of glands or shorter. Achenes dark gray or dull black, obpyramidal, sometimes with sparse, more lucid, laevigate irregular tubercles, ca. 3 × 1.2 mm, with white annular groove at apex, marginal achenes slightly curved. Fl. Apr-Sep, fr. Jun-Nov. 2n = 30, 60.

Fields, thickets, forest margins, forests; 100-2800 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shaanxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [Bhutan, India, Japan, Laos, Malesia, Nepal, Russia, Thailand, Vietnam; Africa, tropical America, Australia, Oceania].