ANATOMICAL ASPECTS OF BEGONIAHYDROCOTYLIFOLIAOTTO EX HOOK. (BEGONIACEAE) LEAF
The paper presents anatomical aspects concerning the leaf structure of Begonia hydrocotylifolia Otto ex Hook. belonging to Begoniaceae family. Anatomically, the petiole has a unistratous epidermis and a differentiated mesophyll. The vascular system is fascicular type with a large number of collateral bundles placed into a basic tissue. The blade consits of an upper epidermis with a many-layerd hypodermis, a lower epidermis and the mesophyll. The mesophyll is differentiated into palisade and spongy tissue with the same vascular bundle structure such as those of the petiole but with foliar arrangement of the conductive tissues. Stomata are present to the lower epidermis. Remarkable are the cytological elements represented by prismatic oxalate crystals, druses, crystalline sand and tannin cells. The mechanical tissue is represented by collencyma cellls, presented in the petiole and blade structure.