| Abstract: | The epidermis and internal structure of 103 species and 8 varieties of conifer leavesbelonging to 37 genera of 7 families have been comparatively investigated. The anatomical characters of leaves of all the genera (or sections) studied are described systematically and a key to the genera (or sections) is also presented. It is shown that in order to identify at the genus level, the leaf types of LaubenFels’ may be used as the primary characterization. And it can also be seen that thefollowing characters which are relatively constant at the genus level provide an important basis for identification: the epidermal structure, the presence or absence ofhypodermis, the degree of differentiation of mesophyll, the occurrence of vascularbundle sheath or endodermis, the transfusion tissue type, the number and relative spatialposition of vascular bundles, the number and distribution of resin canal and the presence of sclereid or sclerenchyma. The genera of Cupressaceae (except for Juniperus and Sabina) are of scale leaves(Leaf type-III) with little differences in structural characters. It’s difficult to distinguish them from each other. In addition, some problems concerning the significance of the resin canal, the endodermis with Casparian-strip, the sclerenchyma and the vascular bundle in identificationare here also discussed. |
