THE VEGETA'l'ION OF NATAL. 307 



close bush is formed. The soil of the slopes, where the bush 

 will grow, is usually covered with large and small blocks of 

 stone. The drainage is good and the soil well aerated, and 

 the stones conserve the moisture. Even in the driest, hottest 

 weather, if a stone be raised, it is seen that the soil is damp 

 underneath. In a protected bush-clearing the various asso- 

 ciated veld plants first take the fielc^, then the half shrubby 

 species get the upper hand, and Senecios, Berkheyas, 

 Plectranthus species, etc., soon almost entirely exclude the 

 grasses. Among these the various bush trees grow up and 

 the slope gradually becomes covered with bush. 



(8) ROCKY STREAM FLORA. 



Differing considerably from the types of bush already 

 described is that which occurs in the rocky stream valleys. 

 The streams flow through it, and each side of the valley is 

 covered with bush. Often, howevei*, the side which is more 

 exposed to the hot dry winds is bare of trees except close to 

 the bed of the stream. In places the canopy is dense, but 

 there are open spaces that have almost full exposure to the 

 sun. When the amount of sunlight which penetrates to the 

 ground is measured it is found to vary considerably. (See 

 above" under " Light.") 



The following lists of trees represent the composition of 

 this type of bush in the different regions. 



(a) Rocky Stream Flora, Coastwards. 



Eugenia cor data, 

 Trema bracteolata, 

 Eicus capensis, 

 Ficus natal ensis, 

 Myrica asthiopica, 

 Voacanga thouarsii, 

 Halleria elliptica, 

 Combretum salicifolium . 



