io6 Plants and their Ways in South Africa 



protecting its stomata. The cells bordering the stomata over- 

 arch, forming a little hut with an opening at the top (Fig. 89), 

 so small that the vapour can pass 

 out but a drop of rain will not run 

 in. 



The heaths have small needle- 

 shaped leaves ; their edges are rolled 

 back so as to form partially enclosed 

 channels on the under side where 

 the stomata are placed. These 



FIG. 89. Section of sugar-bush , , , , ... 



leaf through a stoma : a, the channels are protected by a lining 

 guard-cell;^ projecting dome; o f hairs, making sometimes a close 



c, thick cuticle. 



white mat. Many plants have 



strongly ribbed stems ; between which the stomata are placed, 

 so that transpiration is lessened. 



FIG. 90. Crassula pyramidalis, L. 



Our finest heaths are found in the Caledon and Riversdale 



