Study on the Leaf Structure of Hardy Rhododendron

The leaf epidermis structures of hardy Rhododendron in Liaoning were observed under optical microscope.The results showed that they shared the common features as follows:The leaf blades were typical back-abdomen bifacial types, the upper epidermis were formed with one or two layers of bigger cells and the inside layer cell was bigger than the outside one, some upper epidermis were covered with thicker cuticle.There were many stomas distributed in lower epidermis formed with one layer of small cells, while the upper epidermis didn't.The stomata type and distribution density varied in species.The palisade tissue was formed with one or three layers of long column cells lined up densely.The cells of the spongy tissue lined up loosely and had the bigger cell interval.But there were many differences in structure characteristics among plants:the thickness of leaf blade, the stoma size, shape, the type of the stomata distributed, the type of epidermis trichome or gland scales and middle vein vascular bundle, and so on.These structure differences could be used in taxonomy distinguish.