中国黄耆属(豆科)丁字毛类群2新种——额尔齐斯黄耆和沙地黄耆

摘要

Astragalus eerqisiensis Z. Y. Chang, L. R. Xu & D. Podlech and A. shadiensis L. R. Xu, Z. Y.Chang & D. Podlech (Leguminosae) are described and illustrated from Xinjiang,China. Of these,A. eerqisiensis is known only from Burqin County, Xinjiang, and closely related to A. habaheensis, but differs by having rhomboid,obovate or elliptic leaflets which are 15～25(30) mm long, (3) 7～12(15) mm broad,and standard 20～22(25) mm long,wings bilobed at apex. A. shadiensis occurs in Tuokexun County,Xinjiang,and is similar to A. variabilis Bunge ex Maxim.,but differs by its leaves with 5～7(9) leaflets (not 11～19),standard constrict in the middle,and plant very distinctly gray in color. Both species are endemic to China,with A. eerqisiensis belonging to Sect. Helmia Bunge, and A. shadiensis to Sect. Craccina (Stev.)Bunge.%描述了产于中国新疆的黄耆属(Astragalus)丁字毛类群2新种,即额尔齐斯黄耆(Astragalus eerqisiensis Z.Y.Chang,L. R. Xu & D.Podlech)和沙地黄耆(A.shadiensis L. R. Xu,Z.Y.Chang & D.Podlech).其中,额尔齐斯黄耆仅见于新疆布尔津县的额尔齐斯河流域,与哈巴河黄耆(A.habaheensis)近缘,区别在于前者小叶菱形、倒卵形或椭圆形,长15～25(30)mm,宽(3)7～12(15)mm,旗瓣长20～22(25)mm,翼瓣顶端2裂;沙地黄耆产于新疆托克逊县东北部,散生于沙地荒漠,形态上与变异黄耆(A. variabilis Bunge ex Maxim.)接近,区别在于小叶5～7(9)枚而非11～19枚,旗瓣在中部收缩,植株全体被灰色毛而呈灰色.2新种均系中国特有种,其中额尔齐斯黄耆隶属于乌拉尔组(A. Sect.Helmia Bunge),沙地黄耆隶属于旱生组[A. Sect.Craccina(Stev.)Bunge].