Morphological characters of leaf epidermis in schisandraceae and their systematic significance

The leaf epidermis of 23 species belonging to 2 genera within Schisandraceae was investigated using light and scanning electron microscopy. Many characters of the leaf epidermis in Schisandraceae, such as shape of epidermal cells, type of stomata, and cuticular ornamentation, are usually constant within species and thus helpful for elucidating the relationship between and within genera. Leaf epidermal cells are usually irregular or polygonal in shape. The patterns of anticlinal walls are straight, sinuolate, sinuous or sinuate. The stomatal apparatus belong to paracytic or laterocytic type and the latter is subdivided into various subtypes based on the number and arrangement of subsidiary cells. Under scanning electron microscopy observation, the cuticular membrane is often striated, sometimes squamulate or granular; the inner margin of the outer stomatal rim is nearly smooth or denticulate. Evidences from shape of epidermal cells, patterns of cuticular intrusions between the ends of each guard cell of a pair and distribution of stomatal apparatuses support the viewpoint thatKadsura is more primitive thanSchisandra. Study on leaf epidermis also shows thatKadsura interior deserves the rank of a distinct species and the treatment of the evergreen groups, includingS. propinqua andS. plena, as distinct from the deciduous species of the genus is quite natural.