Page:The Journal of Indian Botany.djvu/683

 THE Journal of Indian Botany. Vol. II. SEPTEMBER, 1921. Nos. 3 & 9.

THE PHYSIOLOGICAL ANATOMY OF THE PLANTS OF THE INDIAN DESERT

BY

T. S. Sabnis, B.A., M.SC,

St. Xavier's College, Bombay. (Continued from p. 167). CYPERAC EAE— (Contd.) Scirpus maritimus L— Figs. 311, 312, 313, 314, 315, 316, 317. Margins pointed and protected by stereome bundles. Stomata on both the surfaces of the leaf-blade with the front cavity depressed. Stomata on the leaf-sheaths on the outer side only. Mesophyll in the leaf-blade wholly of palisade cells on either side of stereome gir- ders. Lysigenous cavities alternating with the veins in the leaf-blade and leaf-sheath. Veins in the leaf-blade vertically transcurrent above and below by aqueous cells. Articulation tissue not developed except for aqueous cells on either side of the veins. Mechanical tissue in the leaf-blade forming I-girders, webs being formed by unmixed vascular bundles ; and that in the leaf-sheath in the form of isolated sub-epidermal girders on the outer side above the veins. Veins enclosed in an outer ring of large polygonal colourless cells and of an inner ring of stone-cells. T. S. of the axis triangular. Assimilatory tissue in the axis of palisade cells between stereome girders. Vascular bundles enclosed in rings of stereome. Peripheral bundles apposed to the stereome girders. Mechanical tissue in the form of isolated sub- epidermal girders, those at the angles forming composite large strands. Ground tissue not differentiated in the centre into pith and of cells with granular contents. Structure of the leaf. — The epidermis consists of cells with outer walls flat, greatly thickened and silicified. Inner walls are angular and fit into the sub-epidermal tissue so as to form a com-