Page:The Journal of Indian Botany.djvu/692

226 THE JOURNAL OF INDIAN BOTANY. round smaller veins and arcs on sides of vertically transcurrent veins. Mechanical tissue in the leaf forming sub-epidermal I-girders in association with vertically transcurrent veins and isolated sub-epidermal girders on the lower side. Assimilatory tissue in the axis of palisade cells with a layer of cells resembling sheath-celis on the inner side. Mechanical tissue in the axis in the form of a stereome tube suppli- mented by isolated sub-epidermal I-girders. Webs formed by mixed vascular bundles or by strips of stereome. Larger vascular bundles in the medullary tissue and numerous. Medullary tissue of thin- walled cells.

Gracilea Royleana H. /. Figs. 341, 342, 343, 344. Deeply grooved on both surfaces. Margins blunt with large stereome bundles. Stomata more numerous on the lower surface. Hairs spiny and situated at the angles on the axis. Articulation tissue in the upper half of the mesophyll. All veins vertically transcurrent. Smaller veins with complete sheaths. Mechanical tissue in the leaf forming I-girders. Assimilatory tissue forming arcs above the smaller vascular bundles. T. S. of the axis flattened on the inner side and- semicircular and angled on the outer. Mechanical tissue in the axis in the form a stereome tube supplemented by sub-epidermal I-girders at the angles. Webs formed by mixed small vascular bundles. Larger vascular bundles all embedded in the stereome tube. Medullary tissue of thin- walled cells filled with starch grains.

Chloris villosa Pers. — Fig. 345. Grooves on the surfaces not deep. Epidermal cells toothed. Margins pointed and with small stereome bundles. Hairs spiny. Stomata more numerous on the lower surface. Articulation tissue extending between two surfaces. Palisade tissue forming arcs on sides of the veins. Veins vertically transcurrent. Bundle-sheaths complete round smaller veins. T. S. of the axis elliptical. Assimilatory tissue chlorenchymatous and placed in the plane of longer diameter. Mechanical tissue in the leaf in the form of I-girders and that in the axis in the form of a stereome tube and of a thin sub-epidermal layer of stereome. Smaller vascular bundles embedded in the stereome tube. Larger vascular bundles enclosed in stereome rings and numerous in the medullary tissue ; medullary tissue of thick- walled cells towards the pariphery and of thin-walled cells in the centre.

Eleusine flagellifera Nees.— Figs. 346, 347, 348. Deeply grooved on the upper surface. Margins blunt and with large stereome bundles. Hairs spiny, longer and arising from articulation cells on both sides. Hairs spiny on the axis. Stomata more numerous on the lower surface. Articulation tissue extending between two sur- faces. Palisade cells forming complete girders round smaller veins.