AX CECOLOGICAL SUEVEY OF THE MIDLANDS OF NATAL. 538 



Phragmites association is also the commonest, or one of the 

 commonest, along the rivers. 



(e) Leersia hexandra often forms practically a pure 

 association in wet vleis. It forms a dense mat in autumn 

 covering the surface of the vlei to the depth of a foot or two, 

 and as it dries up during the dry season it is usually burned off. 

 The leaves as they wither are a dark reddish-brown in colour. 



(f) Erianthuscapensis (umtala) is the tallest of all our 

 Natal grasses, growing up to twelve feet or more. It is only 

 occasionally dominant in the vleis, being on the whole more 

 characteristic of the marginal belt of the bush, but where it 

 does occur in the vleis, mixed with Cyperus spp.or other 

 grasses, it is the most conspicuous species on account of its 

 height. 



(g) Cyperus Vleis. — Cyperus latifolius, C. fastigia- 

 tus, and other Cyperus spei-ies form vleis which are of a 

 wet type, but they frequently dry up in winter. 



(h) Typha capensis is dominant in the wettest vleis 

 where the water is stagnant. Such vleis never dry up 

 completely. 



(i) Marsilia macrocarpa may form a covering in small 

 ponds, in which the water, drying up as winter advances, 

 leaves a bed of mud which hardens from the edge inwards 

 towards , the centre. The only examples of this in the 

 selected area occur in the low veld region. 



Marsilia capensis is similarly found near Fox Hill. 



(k) Mixed Associations. — With the exception of the first, 

 these various associations only occur singly in the smaller 

 vleis. In the larger vleis there is a mixture due to the fact 

 that different parts of such vleis vary in their degree of 

 wetness, and in the amount of stagnation in the water. 



In the larger vlei Andropogon associations grow along 

 the margin, and grade into the veld on the other side. With 

 the tall Andropogon species the following grasses are 

 associated : 



Pennisetum sphacelatum, P. thunbergii, Calama- 

 g r o s t i s h u 1 1 o n a?, P h a 1 a r i s a r u n d i n a c e a, A r u n d i n e 1 1 a 



