96 



taut, especially the Kweek grases, Cynodon clactylon, and 

 C. in,compleius . These separately form each extensive 

 consocies and occasionally tliey mix. Pentaschistis aeroid.es, 

 Tristachya leucothrix, Lasiochloa ciliaris, Vulpia bromoides, 



and several other Smith-Western species tend to increase in 

 abundance under the conditions referred to. 



The extent of the South- Western region is indicated on 

 the accompanying map, but it is of course impossible to give 

 exact boundary lines. It includes the portion of the sub- 

 continent from Van Rynsdorp southwards to the Cape and 

 eastward to Humansdorp asd Port Elizabeth, being- bounded 

 towards the interior by the fold mountains which limit the 

 Karroo. There are, however, low-lying patches of Karroo in 

 the midst of it, and on the other hand there are many South- 

 western species which extend eastward along the Roggeveld, 

 Komsberg, and Nieuwveld ranges to the Stormberg, and such 

 species while much diminished in numbers often gain in 

 ecological importance. New endemic forms of South- Western 

 affinities appear, and one species of Danthonia (D. purpurea) 

 has succeeded in establishing complete dominance in the grass 

 veld around Molteno — a fact which will be fully discussed 

 later. The genus Melica assumes great prominence along the 

 above-mentioned mountain ranges. 



On the Western side, northwards from Van Rynsdorp, 

 the Karroo type of vegetation occupies the lower altitudes in 

 Namaqualand, but in the Kamiesberg Mountains south of the 

 Orange River, at altitudes of 2,000 feet and over, there is a 

 very distinct outlier of the South-Western flora, and the fol- 

 lowing grasses all show the affinities with that region, e.g., 

 Danthonia dura, D. tenella, Chaetohromus dregeanus, Penta- 

 schistis lima, P. tomentella, P. filiformis, P. brachyathera, 

 P. euadenia, Avenastram dregeanwn, Ehrharta barbinodis. 



2.— THE WESTERN REGION. 



Not having visited this great region, I am unable to enter 

 into any details regarding the plant succession, and for the 

 information here set forth I have had to rely on the writings 

 of Range, Shinz, Pearson, and others. It is fairly clear that 

 it is by no means of such a uniform type as the Macchia of 

 the South-West or even as the Karroo. In the Namib coast 

 belt and also in the whole southern portion of the region, the 

 climate is very dry, rain falling only at long and irregular 

 intervals. The Namib itself is distinct desert, but the moun- 



