Characters of Leaf Epidermis in 9 Species of Ulmaceae from China

Epidermal characters of mature leaves in 9 species belonging to 6 genera of Ulmaecae were investigated with the help of epidermal maceration and light microscope. The results show that the stomatal apparatus are anomocytic and exist only on the abaxial epidermis in 9 species. Trichomes are mainly divided into glandular hair and non glandular hair. Glandular hairs consist of 1 basal cell, 2 ~ 4 stalk cells and 2 ~ 4 dilated head cells. Non glandular hairs are developed from one cell, yellow cystolith is often found at the base of the trichome, some hairs are very short and take on beaked shape, another hairs are long wimble shape. Based on the above morphological characters, it is not reasonable that Ulmaceae (sensu lato) was divided into two independent families. Meanwhile, the shape of epidermal cells, the pattern of trichomes and the characters of stomatal apparatus vary obviously with species and genera.