THE VEGETATION OP NATAL. 311 



isolated giving the park-like character to the Thorn Veld one 

 fact is very obvious, namely, that the trees often could grow a 

 great deal closer together without interfering with each other. 

 Further, I am informed by Mr. Sim that in cases where the 

 veld has been enclosed and fires prevented the trees do tend 

 to grow close together. But with constant recurring grass 

 tires young trees are scorched, and only isolated ones survive. 

 One factor that might be expected to be in operation would 

 be the lack of sufficient water in the soil — the trees growing 

 in the wetter spots. An examination of the soil, however, 

 shows that there is no such variation. It is uniformly very 

 di'v. 



The grass fires have still another effect. The various seeds 

 of Acacias have a very hard seed coat, audit has been found 

 that seeds often lie for a very long time without germinating. 

 In planting Wattle (Acacia niollissima) it is the practice 

 either to boil or roast the seeds for a short time. Sometimes 

 the following method is pursued. When one Wattle crop is 

 cut down and the bark stripped, the branches and general 

 debris remain scattered over the ground. The seeds are 

 mixed with it and the whole set fire to, when the young- 

 seedlings appear very soon among the ashes. In a similar 

 way after a grass fire the young plants of the various Acacias 

 of the Thorn Veld come up among the ashes. They grow for 

 a year, and then the next grass fire kills some of them while 

 others manage to survive. 



It has already been stated that the isolated thorn trees 

 throw but little shade as compared with that inside the close 

 type of bush, yet the shade that is given is sufficient to change 

 the character of the veld grasses around the base of each 

 tree. Often the change is slight. Anthistiria imberbis 

 and the other veld grasses grow taller. In other cases a variety 

 of other plants are found, e.g. Abu til on sonneritianum, 

 Solanum nigrescens, Sida spp., Cyathula sp., Salvia 

 spp., Leucas sp., Bidens bipartita and many others of 

 the almost innumerable associated veld plants, lists of which 

 are given later. 



