524 -T. W. BRWS. 



recently contained thorn trees. Wherever the soil was 

 suitable for mealie grooving the trees have been removed, and 

 only a few remain. There is very little of the low veld that 

 does not contain some thorn trees. 



In the thorn veld proper the trees grow isolated a few yards 

 apart. Were it not for the grass-fires they would tend to close 

 in and form thorn "thickets." This has been observed to 

 take place in parts of the veld that have been fenced and 

 protected from grass-fires. 



All the thorn trees might have been included in the list of 

 associated plants of the low veld, but there are parts of this 

 veld where there are so few that it is never spoken 

 of as thorn veld. Further, though the trees and grasses, 

 since they occupy the same habitat together, constitute 

 one formation — the thorn veld — yet it is better to con- 

 sider the grasses under the section to Avhich they properly 

 belong — the veld — and to deal with the trees separately, 

 because they naturally compare with the trees that compose 

 the close bush of the high veld region. 



There are probably several species of Acacia which occur 

 abuiidantly enough, but which the Writer has failed to identify 

 owing to not being able to find either flowers or pods. 

 The following species are common : 



Acacia horrida, A. caff ra, A. caffra var. rupestris, 

 A. arabica var. kraussiana, A. sp. (hirtella?), 

 Celastrus buxifolius, Ehretia hottentotica, Zizy- 

 phus mucronata, Cussonia spicata, Hippobromus 

 alata, Euclea undulata, E. sp., Culpurnia sp., Rhus 

 spp., Plectroiiia spp., Sclerocarya caffra, Harpe- 

 phyllum caffrum, Chilianthus dy ssophyllus, Ery- 

 thrina humeana, Nuxia floribunda. Plumbago 

 capensis, Vangueria spp., and the list given as associated 

 plants of the low veld. 



The umbrella-form is typical of these thorn trees. It is 

 the form which seems best adapted to withstand the hot, dry 

 winds to which they are fully exposed. Their extensive root 

 systems extend hoinzontally along the surface of the soil, and 



