关键词: 豆科, 黄耆属, 簇毛黄耆亚属, 叶表皮, 系统学意义

Abstract: The leaf epidermis of 16 species and 1 variety of Astragalus subgenus Pogonophace was investigated by the light microscopy (LM) and partially by the scanning electron microscopy (SEM). The result shows that the stomatal apparatus of these species are present in both abaxial and adaxial epidermis. It is shown that the leaf epidermal cells are polygonal or irregular in shape. The patterns of anticlinal walls are straight, sinuous or sinuate. Based on the shape and the anticlinal wall patterns of the epidermis cells, there are four types of epidermis can be recognized. The four epidermis types are consistent with the sections of Pogonophace to some extent but not all. Under SEM observation, because of the cuticular layer of the leaf epidermis, the stomatal appatatus is at a lower place. The outer stomatal rim and its inner margin of these species are almost the same. In a few species, the cuticular layer of the leaf epidermis has a special appearance. Therefore, this character can be used as a criterion to identify these species in Pogonophace.

Key words: Leguminosae, Astragalus, Pogonophace, leaf epidermis, systematic significance