Page:The Journal of Indian Botany.djvu/62

This page has been proofread, but needs to be validated.

are not found in either of the species. Veins are embedded and are provided with sheaths of thickened green cells. The bundles are accompanied by arcs of collenchyma on the lower side, protecting the phloem of the veins. Hairy covering on the leaf and axis con- sists of densely placed clothing hairs. The hairs are unicellular, two- armed with their thin walls bearing knobs incurstated w :i "h carbonate of lime, fig. 4. The hairs are appressed, filled with air and white ; and protect the plants from insolation by reflecting the rays of light. Glandular hairs do not occur in either of the species.

Structure of the axis.

Epidermis is composed mostly of vertically tabular cells with outer and inner walls greatly thickened and-cuticluarised, much more so in F. macrantha. Lateral walls are thin and undulate.

Primary cortex is characterised by assimilatory tissue composed of short palisade cells in F. jacquemontii (fig. 6) and of palisade tissue on the outer side and chlorencyma on the inner side in F. macrantha (fig. 8). Sclerencymatous pericycle is represented in F. jacquemontii (fig. 6) by a few scattered bast fibres, and in F. macrantha by numer- ous closely placed groups of bast fibres, (fig. 8.) The wood in F. jacquemontii (fig. 6) is quite composite and has vessels uniformly distributed in incomplete rows, the vessels being more numerous and larger in the lower half. In F. macrantha (fig. 8) the vascular ring is undulate and is composed of very small xylem bundles connected by narrow strands of interfascicular wood prosenchyma formed of thick walled cells having small lumina. There are large groups of wood parenchyma enclosing the lower portions of the xylem bundles. Medullary rays do not occur in either of the species.

The pith is composed of thin-walled cells.

Capparidaceae.

Cleome papillosa Steud. Figs. 10, 11, 12, 17, 18. Herbaceous. Epidermal cells with outer walls strongly papillose. Guard cells in the plane of the surrounding cells. Mesopbyll composed of palisade tissue on the adaxial side and of arm-palisade tissue on the abaxial side. Veins not provided with bundle sheaths. Internal glands absent. Glandular hairs multicellular and capitate. Outer walls of the epidermal cells of the axis superficially granulated. Assimilatory tissue in the axis formed of chlorophyll containing parenchyma. Pericycle consisting of long, thin groups of stone cells. Wood composite. Soft bast occuring in groups. Pith formed of thick- walled cells.

(To be continued.)