Abstract: The stem structure, leaf epidermis structure and the pollen morphology of a traditional orien-tal medical herb Orostachys fimbriatus (Crassulaceae) were examined in detail under light microscope and scanning electron microscope and compared with those of Sedum of the same family. According to our anatomical studies, the stems of Orostachys fimbriatus and Sedum spp. consisted of epidermis, cortex and primary vascular tissue. They differed mainly in the size of parenchyma cells, the amount of idio-blasts and the type of vascular bundles. On leaf epidermis, the two distinguished in the shape of surface celis, anticlinal wall and the ornamentation of cuticle while they shared the same type of stomata, aniso-cytic type. As far as pollen morphology was concerned, the two had much the same characteristics such as the pollen shape, angulaperturate, 3-colporate and ornamentation type on the exine surface. But the size and the thickness of exine wall differed distinctly. Some marked differences are taxonomically useful for the identification of genera and division of family. At the end of the article, the author concludes that Orostachys is superior to Sedum spp..

Key words: Orostachys fimbriatus, stem structure, leaf epidermis, pollen morphology