水蛇麻 shui she ma

Urtica villosa Thunberg, Syst. Veg., ed. 14, 851. 1784; Fatoua japonica Blume; U. japonica Thunberg.

Herbs, annual, 30-80 cm tall. Stem erect, few branched or unbranched, green when young, dark with age, puberulous. Petiole puberulous; leaf blade ovate to broadly ovate, 5-10 × 3-5 cm, membranous, appressed hirsute, base cordate to truncate and decurrent on petiole, margin crenate-toothed, apex acute; secondary veins 3 or 4 on each side of midvein. Inflorescences bisexual, cymose, ca. 5 mm wide. Male flowers: calyx lobes ca. 1 mm; stamens exserted. Female flowers: ovary ± depressed globose; style filiform, 1-1.5 mm, 2 × as long as ovary. Achenes ovoid, 3-angled, ca. 1 mm. Fl. May-Aug.

Scrub, grassy areas in wastelands, trail sides, rocks. Anhui, Fujian, Guangdong, Guangxi (Longzhou), Guizhou, Hainan, Hebei, Henan, Hubei, Jiangsu, Jiangxi, Taiwan, Yunnan (Bijiang), Zhejiang [Indonesia, Japan, Korea, Malaysia, New Guinea, Philippines; Australia].