Structural Characters of Leaf Epidermis in Cyrtomium(Fern)

The leaf epidermis of 19 species representing all four subseries of Cyrtomium,and 15 allied groups was investigated under light microscopy,of which twelve species including types of three subseries of Cyrtomium were observed under scanning electron microscopy.The form of epidermal cells of the Cyrtomium was usually polygonal or irregular,with the anticlinal walls nearly straight,arched,sinuolate,sinuous to sinuate.The stomatal apparatus in all species only existed on the abaxial epidermis.The major stomatal apparatus was anomocytic,while diacytic and polocytic types also occurred in Cyrtomium.The stomata on a single leaf belonged to two or more types in most species.Under SEM,the inner margin of the outer stomatal rim ranged from nearly-smooth to sinuolate or erose,and the cuticular membrane of the leaf epidermis was striated,but sometimes with granula.The present study implied that there are no distinct characters of the leaf epidermis to distinguish and diagnose two series and four subseries of Cyrtomium in Shing's classification.