中国-喜马拉雅植物亚区特有物种江孜乌头的分类学订正

Taxonomic revision of Sino-Himalayan endemic Aconitum ludlowii Exell(Ranunculaceae)

关键词:  江孜乌头  毛茛科  中国-喜马拉雅植物亚区  分类学订正  西藏

Key words:  Aconitum ludlowii Exell  Ranunculaceae  Sino-Himalayan subregion  taxonomic revision  Tibet

摘要:

中国-喜马拉雅植物亚区不仅是乌头属植物地理分布的频度中心、多样性中心,原始类群的保存中心、分化中心,而且是特有类群的分布中心。作为该亚区特有物种之一的江孜乌头(Aconitum ludlowii Exell),是Arthur Wallis Exell于1926年根据采自我国西藏江孜的标本发表的新种。其繁殖器官特征及地理分布特点均与原始文献记载(狭域种)不尽一致。为此,对其做分类学修订。该研究应用经典植物分类学方法,进行野外考察、标本采集与鉴定,查阅中国科学院植物研究所植物标本馆(PE)的相关标本并进行形态学观察比较。结果表明:该物种不同标本心皮从无毛、近无毛至被毛,呈现一连续过渡情况。因此,考虑将心皮被毛一类不作为新分类群处理,只在以上研究基础上,做如下修订:心皮5,无毛或上部被毛,西藏拉萨、山南地区、那曲地区及日喀则地区均有分布。该研究结果可为国产乌头属植物的整理以及江孜乌头遗传多样性分析和物种保护提供基础资料。

Abstract:

Aconitum(Ranunculaceae)is a large genus with about 400 species, in which 211 species are in China. The Sino-Himalayan subregion is not only the preservation centre of the primitive groups and species, but also an actively differentiating region of the genus. Described by Arthur Wallis Exell in 1926, A. ludlowii Exell is a stenochoric species restricted to Gyantse(Jiangzi County)in the Rikaze Prefecture of the Southwestern Tibet, and its carpels were glabrous. However according to our survey, morphological observations and taxonomic identification of A. ludlowii Exell in Tibet, the actual situation is more complex. Its carpels were glabrous, subglabrous, or pilose. Mozhugongka County and Nimu County of Lhasa, Langkazi County, Cuona County and Naidong County of Shannan Prefecture, Jiangzi County, Nanmulin County and Yadong County of Rikaze Prefecture and Shenzha County of Naqu Prefectureare in Tibet are the main distribution areas of this species. Therefore, a taxonomic revision of the Sino-Himalayan endemic species is provided as follows: Carpellis 5 glabris vel dimidio superiore pilosis haud patentibus.