FLORA OF EAST AND MIDDLE AFRICA 41 



and Aloe^ arborescent and twining euphorbias, and thorny 

 Commiphora bushes. Immediately bordering the coast 

 tropical belt a grass-covered park-like prairie is found, where 

 the bushes grow far apart and where there is an increase of 

 moisture sufficient to allow a fair growth of grass during 

 much of the year. The sable, Haggard oribi, and the 

 Swahili reedbuck are limited in their distribution to this 

 transitional area. Grassy or park-like plains of small extent 

 occur at intervals throughout all of the nyika, but they 

 form a very small proportion of the area. North of Mount 

 Kenia in the desert country which extends northward to 

 Abyssinia and Somaliland, we find the riparian vegetation 

 quite different from that of the coast nyika, where the dry 

 watercourses are bordered chiefly by green-barked and flat- 

 topped acacias, with only rarely a doum-palm. In this 

 more northern desert we find a heavy growth of doum- 

 palms bordering the dry stream beds and marking their 

 courses amid the low acacia and bush scrub of the desert. 

 Associated with the palms are thickets of the gray Salva- 

 dora persica bushes and groves along the smaller stream 

 beds of Acacia tortilis trees. The wait-a-bit. Acacia melli- 

 fera, with its spreading branches and hooked thorns reach- 

 ing out in every direction to grasp the passer-by, covers 

 most of the desert together with Grezuia populifolia and 

 thorny Commiphora bushes. The baobab is absent from 

 this district. 



On the sides of the hills and mountains this steppe veg- 

 etation is augmented by groves of tall, palm-like Euphorbia 

 nyikcB or the columnar Euphorbia candelabrum^ the flat- 

 topped Acacia stenocarpa, the papery-barked Boswellia 

 trees, and a few aloe bushes. 



