PLANTS OF THE INDIAN DESERT. 1»7 



the veins and in the cortex. Veins vertically transcurrent above and 

 below by sclerenchyma with water-storage tracheid-like structures at 

 their terminations. Clothing hairs tufted and unicellular. Glandular 

 hairs club-shaped with the head divided by horizontal and vertical 

 walls. Pericycle of stone-cells and not composite. Medullary rays 

 1-3 seriate. 



Corchorus trilocularis L.— Fig. 65. Clustered crystals near 

 the veins and few. Glandular hairs club-shaped with the head 

 divided by horizontal and vertical walls. Clothing hairs unicellular* 

 Epidermis of the axis with outer walls considerably thickened and 

 cuticularised. Lateral walls thickened. Wood narrowed on the 

 lower portion of the inclined axis. Medullary rays uniseriate. 



Corchorus antichorus Baens.— Clustered crystals near the 

 veins and few. Clothing hairs unicellular. Glandular hairs club- 

 shaped with the head divided by horizontal and vertical walls. Epi- 

 dermis of the axis with the outer walls greatly thickened and 

 cuticularised. Lateral and inner walls also a little thickened. Medull- 

 ary rays 1-2 seriate. ■ 



Corchorus tridens L.— Figs. 66, 67. Clustered crystals 

 near the veins and numerous. Clothing hairs unicellular. Glandular 

 hairs club-shaped and with the head divided by horizontal walls* 

 Epidermis of the axis with outer walls greatly thickened and with 

 lateral and inner walls also a little thickened. Medullary rays 1-2 

 seriate. 



Structure of the Leaf : — The epidermis of the upper side con- 

 sists of almost cubical cells and of the lower side of horizontally 

 tabular cells. The outer walls are a little thickened ; the inner and 

 lateral walls are thin. The lateral walls are straight. Epidermal 

 C8lls surrounding the sfcomata are usually much smaller and are of 

 the nature of subsidiary cells. 



The stomata are more numerous on the lower surface, while in 

 species of Greiuia they occur only on the lower surface. The guard- 

 cells are elevated and the front cavity is on a level with the surface. 

 In species of Corchorus epidermal cells on either side of the guard- 

 cells are elevated and are much smaller than the ordinary epidermal 

 cells ; they seem to be of the nature of subsidiary-cells. The stomata 

 on the axis are like those on the leaf. 



The mesophyll is composed of palisade tissue on the upper side 

 and of arm-palisade tissue on the lower. 



Oxalate of lime occurs in the form of numerous clustered crystals 

 near the veins in species of Corchorus (fig. 66). In species of Greivia 

 solitary crystals are found near the veins (fig. 63), and in the cortex and 



