FEATURES OF THE MICROSTRUCTURE OF THE LEAVES OF Fatsia japonica (THUNB.) DECNE. ET PLANCH. (Araliaceae)

The internal structure of leaf of the F. japonica that is introduced in Georgia as a source of biologically active substances, was studied, and its microstructural diagnostic signs were determined. F. japonica leaf glabrous, bilateral, dorsoventral, hypostomatic structure. The basal cells of the abaxial and adaxial epidermis of the leaf are non-stitched, curvilinear and curved-walled, the cuticular mosaic of the lower epidermis is wavy. The stomatal apparatus of the Japanese fatsia leaf is anisocytic, the stomatal gap is fusiform, and the location of the stomata is chaotic. A reverse-collateral conductive bundle is imprinted in the pulp of the leaf. In the structural units of all morphological organs of the plant leaf, differentiation of calcium oxalate druse crystals and secretory cells is noticeable. The tissue of the main vein of the leaf of F. japonica is polygonal, the conducting system both in the vein and in the petiole is of fibro-vascular, open-collateral type, but in the main vein bundles are asymmetrical, while in the petiole they are symmetrical and closely interconnected. The  xylem of the main vein and petiole of F. japonica leaf’s has differentiated bulbs arranged in longitudinal rows. Xylem conductive vessels with spiral, ring and mesh thickenings of the shell are observed lengthwise the petiole.