Page:The Journal of Indian Botany.djvu/94

68 on the margin of the leaf. They are numerous and longer on the axis than on the leaf (fig. 26). In Cleome brachycarpa there are a few multicellular glandular hairs with a spiny curved apex (fig. 20).

Structure of the Axis Epidermis consists of small cells with outer and inner walls thickened. Lateral walls are also thickened in Cleome papillosa and Cadaba indica. Epidermis is two-layered in Gynandropsis pentaphylla. Outer walls are superficially granulated in species of Cleome. Epidermis of Capparis decidua consists of vertically elongated small cells with outer walls greatly thickened and cuticularised. Epidermis of Capparis decidua is characterised by numerous small pits which in T. S. are bounded laterally by two ordinary epidermal cells and beneath by a curved cell. Viewed from the surface the pits resemble small square holes bounded by 4-5 cells. These pits may possess the function of stomata without any regulating apparatus. The axis of Cleome brachycarpa and Cleome viscosa is ribbed, the ribs being strengthened by collenchyma. In Cleome brachycarpa there are some large cells intercalated among the small epidermal cells of the ribs with perhaps partly a water-absorbing and partly a strengthening function.

The stomata are surrounded by 4-6 ordinary epidermal cells as seen in surface view. The front cavity is placed in a depression produced by the outer thickened epidermal walls. The guard-cells are in the plane of the surrounding cells. Stomata are replaced by pits in Capparis decidua, as described already.

Primary cortex is characterised by an assimilatory tissue composed of chlorenchyma, except in Capparis decidua where it is replaced by the palisade tissue. In Capparis decidua there are sclereids in a ring below the assimilatory tissue. The sclereids have thickened and radially striated walls and are characterised by pitted markings.

The pericycle is represented by groups of stone-cells, either thin and long as in Cleome brachycarpa and Cleome papillosa, or triangular as in Cleome viscosa or rhomboidal as in other species.

The structure of the wood can be seen from the following table. (p. 71.)

The soft bast forms a continuous ring as in Cleome brachycarpa, Cadaba indica and Gynandropsis pentaphylla, or forms groups as in other members.

The pith is either composed of thin-walled cells as in Cleome brachycarpa, Cleome viscosa and Gynandropsis pentaphylla, or of thick-walled cells, as in other species.