74 THE JOURNAL OF INDIAN BOTANY. 



Internal secretory organs are represented by secretory cells with 

 tanniniferous contents in the leaf and axis. In the leaf they are poly- 

 gonal and lie in the lower half of the mesophyll. In the axis there is a 

 sub-epiderma) secretory tissue of one or two layers of tabular cells. 

 Besides, there are numerous outer sclerenchymatous fibres and 

 numerous pith cells with tanniniferous contents. Some of the cells 

 of the medullary-ray-like strands also hold tanniniferous contents. 

 The secretory cells with tanniniferous contents seem to be a charac- 

 teristic feature of the species. 



Oxalate of lime is abundantly found in the form of large cluster? 

 ed crystals near the veins in the leaf. In the axis cells with clustered 

 crystals occur in the outer sclerenchymatous fibres, in the cells of tie 

 medullary-ray-like strands and in the pith. 



The abundance of tanniniferous substance and of oxalate of lime 

 in the leaf and axis gives an acrid taste to the tissues of the plant and 

 makes it inedible by animals. Abundance of tannin also protects the 

 tissue of the plant from desiccation. The veins are enclosed in green 

 bundle-sheaths. Larger veins occur as usual in the middle of the 

 mesophyll. Besides these, there are smaller veins near the lower 

 epidermis. The vein of the mid-rib is protected above and below by 

 strands of sclerenchyma and is vertically transcurrent below by 

 colourless parenchyma. 



The leaf and axis are devoid of clothing and glandular hairs. 



Structure of the Axis : — The epidermis consists of small tabular 

 cells with outer and inner walls very greatly thickened. Outer walls 

 are convexly arched outwards. Lateral walls are straight. The 

 cuticle is thick and smooth. 



The cortex is characterised by a sub-epidermal tissue of tabular 

 cells with tanniniferous contents. The assimilatory tissue which lies 

 below the secretory tissue is composed of chlorophyll containing 

 parenchyma. 



The pericycle is composed of large groups of stone cells situated 

 on the radii of the vascular bundles. Besides these pericyclic groups 

 of stone cells, there is a tissue of sclerenchymatous fibres with larger 

 lumina, continuous with the medullary-ray-like structures between 

 the vascular bundles. There are a few scattered stone cells with 

 walls much thickened and radially striated and with small lumina, on 

 the outer margin of the sclerenchymatous tissue and in the soft bash 



The wood is composed of large xylem bundles separated by 

 broad strands of radially elongated thick-walled cells resembling 

 medullary-ray cells. These seem to be continuous with the scleren- 

 chymatous tissue outside the pericyclic groups of stone cells. ) 



There are isolated cases of sclerotic cells with canals, as large 



