关键词: 荨麻科, 楼梯草属, 新组, 新种, 重庆

Abstract: One section and three species of the genus Elatostema (Urticaceae) are described as new from the Simian mountain, Jiangjin district, Chongqing city:(1) Sect. Gynosciadion with one species, Elatostema femineocymosum, is chracterized by its numerous pistillate flowers in a 3-4 times branched cyme, lacking a receptacle with an involucre, and by these charactes can be distinguished from all other sctions of the genus Elatostema; (2) E.gyronanophyllum is closely related to E.sinense H. Schröter, differing from the latter in its smaller leaves with fewer secondary nerves, orbicular or suborbicular reduced leaves, pistillate involucre with 12 triangular bracts, pistillate flower with 2 tepals, and the depressed-globose stigma; (3) E.zhengyuanum is closely related to E.simianshanicum W.T.Wang, differing from the latter in its glabrous, sometimes vegetative stems, larger leaf blades, cystoliths and stipules, and oblanceolate-oblong bracts of staminate involucre not carinate abaxially.

Key words: Urticaceae, Elatostema, new section, new species, Chongqing