荨麻科三新种

Three new species of Urticaceae

关键词:  荨麻科, 荨麻属, 赤车属,楼梯草属, 新种, 中国, 缅甸

Key words:  Urticaceae, Urtica, Pellionia, Elatostema, new species, China, Myanmar

摘要:

该文描述了荨麻科三新种:(1)自中国重庆市发现的荨麻科荨麻属一新种,城口荨麻。此种与异株荨麻有亲缘关系,区别特征为此种的茎被少数刺毛,叶片多为心形,雄、雌花序均不分枝,瘦果在中央稍凹陷。(2)自中国广西发现的荨麻科赤车属一新种,来宾赤车。此种与特产云南东南部的富宁赤车相近缘,与后者的区别在于本种茎的毛开展或向上弯曲,叶片长椭圆形,基部斜楔形,雌花具3～4枚花被片,其中1～2枚较大花被片在背面顶端具一长筒状突起。(3)自缅甸北部发现的荨麻科楼梯草属一新种,克钦楼梯草。此种在体态上与骤尖楼梯草甚为相似,与后者的区别在于本种的每一茎节具正常叶和一退化叶,托叶狭披针状条形和无脉,雌总苞苞片无角状突起,雌小苞片较大,呈楔状长圆形,雌花具一小花被片,以及雌蕊具一宽倒卵球形柱头。

Abstract:

Three new species of Urticaceae are described in this paper:(1)A species of the genus Urtica (Urticaceae), U. chengkouensis, is described as new from Chongqing City, China. This species is related to U. dioica L., from which it differs in its stem with few stinging hairs, its mostly cordate leaf blades, its unbranched staminate and pistillate inflorescenes, and its achenes which are slightly impressed at the centre.(2)A species of the genus Pellionia(Urticaceae), P. laibinensis, is described as new from Guangxi Zhuang Autonomous Region, China. It is related to P. funingensis W. T. Wang, endemic to Southeast Yunnan Province, and from the latter differs in its stem, which is covered with spreading or antrorsely curved hairs, its long elliptic leaf blade with obliquely cuneate base, its pistillate flower with five tepals, and the one or two larger tepals of them abaxially from apex with one tubular projection.(3)A species of the genus Elatostema (Urticaceae), E. kachinense, is described as new from northern Myanmar. This species in habit is very similar to C. cuspidatum Wight, and from the latter differs in its stem node with a normal leaf and a reduced leaf, narrowly lanceolate-linear nerveless stipules, uncorniculate pistillate involucral bracts, much larger cuneate-oblong pistillate bracteoles, pistillate flower with a minute tepal, and pistil with a obovoid stigma.