Characters of Leaf Epidermis and Their Systematic Significance in Bupleurum from China

Leaf epidermis of 13 species in the genus Bupleurum L.was examined under both light microscope(LM) and scanning electron microscope(SEM).Stomatas of most species occur in both abaxial and adaxial epidermis,and only B.longiradiatum Turczaninow has stomatas in abaxial epidermis.The shape of epidermal cells in Bupleurum examined are generally polygonal,and the anticlinal cell walls are either straight or curved.Only a few species are irregular,with the anticlinal cell walls sinuolate.Guard cells have thickened walls,forming polar lamellae at the polar end.Under the SEM,the cuticular membrane in the genus is usually striated.The wax ornamentations are flaked,striate to wrinkled or granular.These uniform micromorphological characteristics in the genus are important in classifications of studied species.