重庆楼梯草属一新组和三新种  

One New Section and Three new species of Elatostema( Urticaceae) from Chongqing

作　　者：王文采[1] WANG Wen-Tsai(State Key Laboratory of Systematic and Evolutionary Botany,Institute of Botany,Chinese Academy of Sciences,Beijing 100093)

机构地区：[1]中国科学院植物研究所系统与进化植物学国家重点实验室,北京100093

出　　处：《植物研究》2018年第6期804-808,共5页Bulletin of Botanical Research

摘　　要：描述了自重庆市江津区四面山发现的荨麻科楼梯草属的一新组和三新种:(1)雌伞楼梯草组Sect.Gynosciadion具一新种,雌伞楼梯草Elatostema femineocymosum,其特征为雌花序为3～4回分枝的聚伞花序,无花序托和总苞,根据这些特征可与楼梯草属的其他组相区别;(2)圆微叶楼梯草E. gyronanophyllum,与对叶楼梯草E. sinense H. Schr?ter近缘,区别特征为此新种的叶较小,具较少二级脉,退化叶圆形或近圆形,雌总苞具12枚三角形苞片,雌花具2花被片,柱头扁球形;(3)正宇楼梯草E. zhengyuanum,与四面山楼梯草E. simianshanicum W. T.Wang近缘,区别特征在于新种的茎无毛,有时为营养茎,其叶片、钟乳体和托叶均较小,雌总苞的苞片呈倒披针状长圆形,在背面无鸡冠状突起。ne 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.Schr ter,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.

关 键 词：荨麻科 楼梯草属 新组 新种 重庆 

分 类 号：Q949.737.5[生物学—植物学]