THE 



Journal of Indian Botanp* 



Vol. I. MAY, 1920. Nos. 9 & 10. 



THE PHYSIOLOGICAL ANATOMY OF THE 

 PLANTS OF THE INDIAN DESERT 



BY 



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



St. Xavier's College, Bombay. t 

 (Continued from p. 2i7.) 



LYTHR ACE \E—(Contd.) 



The mesophyll is composed of palisade tissue on the upper side 

 and of arm-palisade tissue on the lower. Internal secretory organs 

 are not found. Oxalate of lime occurs in the form of clustered cry- 

 stals near the veins in A. desertorum. 



The veins are embedded and are enclosed in green bundle- 

 sheaths. 



Hairy covering is found on the axis and on bhe upper surface of 

 the leaf of A. desertorum and consists of unicellular conical hairs with 

 verrucose walls and sometimes seated on a group of two or three 

 epidermal cells (fig. 126). Glandular hairs are not found. 



Structure of the Axis : — The epidermis is composed of tabular 

 cells with outer walls thickened, verrucose and convexly arched out- 

 wards. The inner walls are thickened; and the lateral walls are thin 

 and straight. The axis is ribbed at the angles. The cortex is com- 

 posed of chlorenubyma extending to the ribs. 



The pericycle forms a loose ring of bast fibres, those in A. bacci/era 

 having thin walls and large lumina. The wood is composite. The 

 vessels are uniformly distributed in incomplete rows, vessels becoming 

 larger towards the inner margin of the wood. The interfascicular 

 wood prosenchyma is composed of cells with thin walls and large 

 lumina and is more extensive in the upper half. The medullary rays 

 are uniseriate and numerous. Wood parenchyma is abundantly 

 developed at the inner margin of the wood cylinder. 



