Leaf Epidermal Morphology and Taxonomic Significance of Euonymus L. in China

The leaf epidermal characteristics of 24 species of Euonymus and 3 species of Glyptopetalum in China were investigated using light microscopy(LM) and scanning electron microscopy(SEM).The stomatal ratio of length to width,density and index were measured.The results revealed that the epidermal structure is of the same type in the two genera: most of adaxial and abaxial epidermal cells are polygonal shapes,and their anticlinal walls are mainly straight-arched;The stomatal apparatuses only present on the abaxial epidermis for most sampled species.The stomata are anomocytic.However,in some species,the stomata are cyclocytic.Under SEM,the cuticular membrane,cell boundary of the leaf epidermis and stomatal structure are different among some species,which may be referred for the systematic relationships and classification of Euonymus.