LEAF ANATOMIC STRUCTURE OF ERVATAMIA DIVARICATA AND ITS ECOLOGICAL SIGNIFICANCE

The leaf anatomical structure of Ervatamia divaricata(L.) Burk.cv.Gouyahua was studied by cryosectioning method and optics microscope.The results indicate that the leaves are typical bifacial leaf and display some characteristics of sun leaf(dry leaf) and shade leaf in the morphology and the anatomy.Each epidermis consists of one layer of epidermic cells closely arranged which have cuticle on the ektexine.The stomata exist mainly in lower epidermis,only a few stomata exist in upper epidermis,and the stomata apparatuses are paracytic type.The mesophyll tissue is very rich and contains crystals,the palisade tissue is composed of 1-2 layers of cylindrical cells,the spongy tissue interweaves to form reticular formation and the intercellular space is developed.The ratio of the palisade tissue to the spongy tissue is 0.32:1.The vascular bundle of midrib is the amphicribral vascular bundle which is rather developed.All these characteristics indicate that the plant's leaf structure is well adapted to its growing environment.