100 THE JOURNAL OF INDIAN BOTANY. 



Sfcomata occur on both the surfaces, being a little more numerous 

 on the lower. Guard-cells are elevated above the plane of the sur- 

 rounding cells and the front cavity is a little raised above the surface. 

 Btomata are surrounded by 3-4 ordinary epidermal cells. 



The mesophyll is composed of short palisade cells on either side 

 without a middle tissue except for a layer of polygonal cells contain- 

 ing clustered crystals in the middle of the mesophyll in B. odorata. 



Internal secretory cells are not found in the leaf. Oxalate of 

 lime occurs in the form of numerous clustered crystals near the veins. 

 In B. odorata there is a layer of polygonal cells with clustered cry- 

 stals in the middle of the mesophyll (fig. 51). In the axis clustered 

 crystals occur in the cortical parenchyma and pith. Veins are 

 provided with sheaths of green thick-walled cells. Larger veins are 

 vertically transcurrent above and below by colourless parenchyma. 



Hairy covering on the leaf and axis consists of clothing and 

 glandular hairs. Clothing hairs are partly unicellular and partly 

 uniseriate trichomes. They are not found on the leaf of B. ammani- 

 oides and those on the axis are very thin-walled. Glandular hairs 

 occur only in B. odorata and are of a shaggy type ; they are composed 

 of a multicellular stalk and of a multicellular head (figs. 51, 52). 



Structure of the Axis : — The epidermis is two-layered. Outer 

 epidermal cells have outer walls greatly thickened, the lateral walls 

 being thin. The stomata are like those on the leaf and are surround- 

 ed by 4-5 ordinary epidermal cells. The primary cortex is charac- 

 terised in its outer portion by an assimilatory tissue, which in B. 

 odorata (fig. 52) is composed of short palisade cells and in B. ammani- 

 oides (fig. 66) of chlorenchyma. Inner portion of the cortex is formed 

 of large-celled cortical parenchyma. 



The wood in both the species presents a quadrangular appearance. 

 It is broader at the angles and is much narrowed between. Inter- 

 fascicular wood prosenchyma is extensive. The medullary rays 

 occur in B. odorata and are 1-2 seriate. The vessels are arranged in 

 rows. Wood parenchyma is scantly developed. 



The pith is composed of thin-walled cells. Internal secretory 

 organs are represented by secretory cells with tanniniferous contents. 

 They occur in the cortical parenchyma in the soft bast and pith of B. 

 odorata and only in the pith of B. ammanioides. 



MALVACEAE 



Sida grewioides Guill. — Figs. 53, 54. Woody. Stomata more 

 numerous on the lower surface. Internal glands numerous in the 

 mesophyll. Clustered crystals occurring near the veins of the leaf 

 and in the soft bast of the axis. Clothing hairs tufted and more 



