Abstract: The leaf epidermis of 15 species, representing two sections of the genus Cotoneaster was investigated using light microscopy(LM) and scanning electron microscopy(SEM). In Sect. Cotoneaster, leaf epidermal cells are usually polygonal in shape, straight to arched in pattern of anticlinal wall, and the stomata are anomocytic. While in Sect. Uniflos, leaf epidermal cells are usually irregular in shape, repand or sinuous in pattern of anticlinal wall, the stomata are anomocytic, and staurocytic, tetracytic, isotricytic besides. The fifteen species can be divided into three types: type W, type S, and type I, according to the characters of cuticular membrane surrounding the stomata and the other epidermal characters. Type W is an exceptional type S. Plants of Sect. Cotoneaster investigated here are type W or type S, while plants of Sect. Uniflos belong to type I. The characters mentioned above are of much significance in delimiting sections and species in Cotoneaster.

Key words: Cotoneaster, leaf epidermis, taxonomic significance