THE VEGETATION OF NATAL, 295 



The vegetation clothing them rises almost from sea-level to 

 a height of 20 to 25 feet above ground on the tops of the 

 dunes. Further, though the surface of the dunes may be 

 irregular and hummocky, the trees rise more or less to the 

 same level, so that viewed from the sea-shore side the bush 

 presents a singularly regular and even appearance. 



On the side next the sea there is a certain admixture of the 

 plants named as occurring among the Pes-Caprae and 

 Mesembryanthemum associations. The Mesembry- 

 anthemum itself may often be found straggling up into the 

 bush. The following plants, together with the list already 

 given, may be taken as characteristic of the sea-side marginal 

 belt of the bush : 



C a n a V a 1 i a 1 ) o n a r i e n s i s , M i m u s o p s c a f f r a , E u g e n i a 

 capensis, Cassine albanensis, Cynanchium crassi- 

 folium, C. capense, Celastrus procumbens, C. angu- 

 laris, Carissa grandiflora, Chironia baccifera, Aloe 

 supra-l^vis, Rhvis spp., Passerina spp. 



The bush itself, as mentioned above, consists of trees that 

 all grow more or less to the same height ; there is no second 

 canopy or undershrubs, and very little undergrowth of any 

 kind. There is, however, an enormous variety of lianes, as 

 shown by the list given. A certain amount of humus gathers 

 round' the roots of the trees, and forms a layer of sandy turf 

 about six inches in depth. Below this is the dune sand. 

 Its nature has already been described. The roots of the trees 

 descend to great depths, and the whole root-system is 

 extensively developed. This is well seen in places where, as 

 sometimes happens, the sea has eaten into the bush dunes. 

 Then the root-system is exposed, and is seen to descend 

 20 feet or more. Above ground the vegetation is of the 

 usual halophytic character, and the fleshy type of leaf is 

 common. The loose character of the sand gives thorough 

 aeration, and consequently the roots of the trees are able to 

 penetrate to such great depths. This is necessary to procure 

 proper fixation. The sand is, as a rule, not very dry, since it 

 is kept moist by the frequent precipitation. 



