目的:通过研究景天属4种药用植物及2种混淆品的叶表皮显微特征,为它们的鉴别提供依据,并进一步探讨气孔参数在药用植物鉴别中的价值。方法:利用叶表面片显微鉴别的方法,比较它们(部分种包括不同采集地的样品)的叶表皮细胞形态及气孔参数(包括气孔指数、气孔密度和气孔长宽比)的共性与差异,确立鉴别特征。结果:6种植物叶除具有部分共性特征外,在叶片上下表皮细胞的形态、排列状况、气孔分布以及叶缘细胞的形态上有各自的特征。结论:可综合利用叶片、叶脉、叶基部及叶缘细胞的形态特征及排列状况将景天属4种药用植物及2种混淆品一一鉴别;气孔指数与气孔密度对景天属药用植物的分类鉴定意义不大。 Objective: To study the microscopic characteristics of leaf epidermis of four medicinal plants of Sedum and two kinds of adulterants, to provide basis for their identification and to further explore the value of stomatal parameters in the identification of medicinal plants. Methods: The leaf epidermal cell morphology and stomatal parameters (including stomatal index, stomatal density and stomatal aspect ratio) were compared by using the method of microscopic identification of leaf surface slices. Establish identification features. Results: In addition to the common features of some plants, the morphology and arrangement of the upper and lower epidermal cells in the leaves of the six species had their own characteristics in the distribution of stomata and the morphology of the leaf margin cells. CONCLUSION: The morphological characteristics and arrangement of the leaf cells, leaf veins and leaf margin cells of the genus Sedum can be synthetically used to distinguish the four medicinal plants of Sedum and the two kinds of adulterated ones. The stomatal indices and stomatal density of the two medicinal plants Plant classification identification of little significance.