Page:The Journal of Indian Botany.djvu/92

Rh Veins provided with green sheaths. Glandular hairs multicellular and capitate. Epidermis of the axis two-layered. Pericycle formed of rhomboidal stone-cell groups. Wood composite. Soft bast forming a continuous ring. Pith formed of thin-walled cells.

Cadaba indica Lam. Figs. 30, 31, 32, 33, 34, 35. Woody. Outer walls of the epidermal cells of the leaf greatly thickened and papillose. Guard-cells in the plane of the surrounding cells. Mesophyll formed wholly of short palisade cells. Internal glands in the leaf in the form of parenchymatous cells with tanniniferous contents. Veins not provided with sheaths. Water-storing tracheids occurring at the terminations of the veins. Clothing hairs peltate. Glandular hairs absent. Outer walls of the epidermal cells of the axis superficially granulated and lateral walls thickened. Pericycle formed of rhomboidal groups of stone-cells. Wood forming a composite ring; soft bast forming a continuous ring.

Capparis decidua Pax. Figs. 27, 36, 37. Woody. Leaves occurring only on young shoots. Epidermis of the leaf and axis formed of vertically elongated highly thick-walled cells. Mesophyll isobilateral with an extensive middle tissue of parechymatous cells. Internal glands in the form of numerous cells with tanniniferous contents. Veins not provided with sheaths. Pits present in the epidermis of the axis. Assimilatory tissue in the axis formed of palisade cells. A ring, 1-2 cell thick, of sclereids occurring below the assimilatory tissue. Pericycle formed of rhomboidal groups of stone-cells. Wood formed of xylem bundles connected by strands of interfascicular wood-prosenchyma. Soft bast forming groups. Pith composed of thin-walled cells.

Structure of the Leaf Epidermis.—Outer walls are thickened and somewhat papillose in all members except Cleome viscosa (fig. 16.) The thickening and papillose differentiation is considerable in Cleome papillosa (fig. 11), Cadaba indica (fig. 30), Gynandropsis pentaphylla (fig. 22) and Capparis decidua. Lateral walls are thin in all the numbers except Capparis decidua, where they are thickned; they are somewhat undulate in all the members. Epidermal cells at the margin are rounded forming the marginal epidermis compact and rigid. Some of the lower epidermal cells in Cleome brachycarpa are larger and longer than broad, perhaps serving as water-reservoirs. Epidermal cells at the margin and along the mid-rib are smaller than in the other part of the leaf blade.

Stomata are surrounded by four to six ordinary epidermal cells (fig. 19) and are more numerous on the under surface. They are placed in depressions formed by the outer thickened and papillose