黄耆属簇毛黄耆亚属系统学研究

簇毛黄耆亚属以其柱头上具簇毛等形态特征与黄耆属其它类群相区别，约含49种（变种）。主要分布在青藏高原及其邻近地区，绝大多数种类分布于横断山区。本文基于形态特征和分支系统学方法分析亚属内种系发生关系。结果表明，49种（变种）可分为9组。其中双小苞组Sect.Bibracteolati含种类最多，是一个并系类群。借助于分支图，分析了6个较重要的鉴定特征的演化，习性，茎的着生方式，小苞片，果实形态，柱头具簇毛，果实膨胀状况等。最后作出了这个亚属的一个分类纲要。

Systematics of Astragalus Subgenus Pogonophace (Leguminosae)

Subgenus Pogonophace,a distinctive group in Astragalus ,is characterized mainly by its bearded stigma.There are forty nine species and varieties in this subgenus and they are distributed mainly in Qinghai Xizang (Tibet) Plateau and its adjacent region, most species occur in Hengduan Mountains of southwestern China.Forty nine taxa in Pogonophace were treated as the terminal taxa and thirty three morphological characters were employed to do the cladistic analysis in the present paper.The results showed that nine sections establishing in the subgenus would be available.Sect.Bibracteolati,a complex section with more than twenty species,formed the paraphyletic group on the cladogram.Six character evolution cladograms are given respectively based on six key diagnostic characters in the subgenus,namely habit,growth pattern of stem,bracteole,fruit shape, stigma bearded, and fruit inflation.Finally an outline of classification system outline of this subgenus is presented.