CHAPTER VI 



LEAVES 



Leaves collectively constitute the greatest manufacturing 

 plant in the world. Most of the food, clothing, and medicine 

 used by man is formed as a result of the work of the leaf. The 

 cell contents, structure, and arrangement of the different cells 

 of the leaf differ in a marked degree from the cell contents, 

 structure, and arrangement of the cells in the other organs of 

 the plant. This accounts for the presence of the large amount 

 of chlorophyll in the leaf, the presence of stomata, and the 

 peculiar arrangement of the cells. 



It should be ascertained if the stomata are above, even with, 

 or below the epidermis; the nature of the epidermal cells, and, 

 when present, the nature of the hypodermal. cells; the number of 

 layers of palisade parenchyma and whether it is present on 

 both surfaces of the leaf, and the nature of the outgrowths from 

 the epidermal cells. 



KLIP BUCHU 



The cross-section of klip buchu (Plate 108) has the following 

 structure : 



Epidermis. The epidermal cells of klip buchu are modified 

 to form papillae, the walls are yellowish white, and the papillate 

 portion of the cell is nearly solid. 



Hypodermis. The hypodermal cells are never intact because 

 the mucilage contained in the cells swells when placed in water 

 and breaks the thin side walls. 



Upper Palisade Parenchyma. The palisade parenchyma is 

 two layers in thickness. The cells of the outer layer are greatly 

 elongated and are packed with chlorophyll. The inner layer 

 of palisade cells is more irregular, and the cells are much shorter 

 than the cells of the outer palisade layer. 



Spongy Parenchyma. The spongy parenchyma cells are 



260 



