312 J. W. BEWS. 



As in the case of tlie close bush it was found that the rocky 

 stream type differed considerably from the ordinary type, so 

 also in the Thorn Bush there are types that differ from the 

 usual one as described above. One such type is common. It 

 is found on dry slopes fully exposed to the hot winds 

 up to an altitude of 2000 ft. or more. The species composing 

 it grow scajttered as in the typical thorn veld^ or close 

 together forming a dense, but at the same time extremely 

 xerophytic type of bush. 



It is made up of the following : 



Euphorbia g r a n d i d e n s, 



Euphorbia tirucalli, 



Schottia brachypetala. 



Aloe marlothii, 



Celastrus buxifolius, 



Commiphora harveyi, 



Acacia caffra var. rupestris, 



Acacia horrida; 

 with the lianes : 



S a r c o s t e m m a v i m i n a 1 i s, 



Dregia floribunda, , 



Vitis cuneifolia, 



Capparis spp., 



Pelargonium peltatum. 

 Of these, several have been described as being found in 

 the typical Thorn veld. The others are very xerophytic. 

 Euphorbia gr audi dens has the candelabra form and is 

 practically leafless. Sarcostemma viminalis is also 

 leafless. The Euphorbias contain a resinous caoutchouc 

 which can be extracted in quantity, and in the case of 

 Euphorbia tirucalli is being Avorked by a rubber com- 

 pany. 



Another xerophytic type is found on mountain rocky situa- 

 tions consisting of : — 



(xreyia sutherlandi. 



Aloe natalensis, 



Buddleia salvia^f olia, 



