numerous on the lower surface. Glandular hairs pitcher-shaped and more numerous on the lower surface. Cortex characterised by cork and collenchyma. Assimilatory tissue formed of chlorenchyma. Bast fibres occurring in the soft bast. Wood uniformly broad. Medullary rays uniseriate. Pith formed of thin-walled cells.
Abutilon fruticosum Guill.—Figs. 55, 56. Woody. Stomata numerous on both sides. Internal glands absent. Clustered crystals found near the veins of the leaf and in the collenchyma, soft bast and pith of the axis. Clothing hairs tufted and equally numerous on both sides. External glands club-shaped and equally numerous on both the sides. Cortex characterised by cork and collenchyma. Wood uniformly broad. Vascular bundles occurring in the pith. Medullary rays 1-3 seriate. Pith formed of thick-walled cells.
Pavonia arabica Steud.—Woody. Stomata more numerous on the lower surface. Secretory cavities numerous in the mesophyll. Clustered crystals abundant in the leaf and axis. Clothing hairs tufted and more numerous on the lower surface. Tufted hairs along with simple thick-walled unicellular hairs found on the axis. Assimilatory tissue formed of chlorenchyma. Bast fibres occurring in the soft bast. Wood reduced on the lower side of the inclined axis. Medullary rays uniseriate. Pith formed of thin-walled cells.
Hibiscus micranthus Lf— PI. VIII, figs. 57, 58. Woody. Stomata more numerous on the lower surface. Internal glands absent in the leaf and axis. Clustered crystals found near the veins in the leaf, and in the collenchyma and pith of the axis. Clothing hairs tufted. External glands club-shaped and few on the leaf and axis. Assimilatory tissue formed of palisade cells. Cortex characterised by collenchyma. Sclerenchymatous pericycle and wood reduced on the lower side of the inclined axis. Medullary rays 1-3 seriate. Pith formed of thin-walled cells.
Gossypium herbaceum L— Figs. 59, 60. Woody. Stomata more numerous on the lower surface. Internal glands in the leaf and axis in the form secretory cells and secretory cavities. Some of the pith cells holding tanniniferous contents. Clothing hairs tufted. Glandular hairs spherical and more numerous on the upper surface of the leaf and numerous on the axis. Cork subepidermal. Sclerenchymatous pericycle and wood reduced on the lower side of the inclined axis. Medullary rays 1-3 seriate. Pith formed of thin-walled cells.
Structure of the Leaf:-Epidermal cells are tabular with outer-walls thickened and papillose. Lateral walls are straight. The surface of the leaf in Abutilon fruticosum is characterised by ridges and furrows. There are cells of considerable dimensions with water-
