SUDANESE SAVANA 211 



of the Great Lakes, and round across the whole of the 

 Zambezi region back to the Atlantic. It results from the 

 tropical climate with a moderate amount of rainfall and 

 a long spell of drought. 



Though the series of trees, shrubs, grasses, and herbs 

 changes, the savana preserves throughout, despite differ- 

 ences of detail, its main characteristics of tall grass- 

 land dotted with deciduous trees and bushes, either 

 dispersed or in woods. So gradual are the transitions 

 from the poorest to the richest forms of vegetation ; 

 from the desert lands, whether of Sahara, Somali, or 

 Kalahari, to the dark selvas ; that any sharp boundary 

 between the semi-desert and the savana. or between the 

 latter and the light tropical woodland, is out of the 

 question. Representative forms and formations of the 

 desert and the semi-desert continue for a time to 

 intermingle with the specific savana vegetation, while 

 isolated members of the high forest penetrate far into 

 the park-land. 



The Sudanese savana belt extends from Senegal to the 

 Upper Nile amid a varied landscape, now of high table- 

 lands, now of lower plains. Some kind of acacia, 

 mimosa, or allied tree is always in sight, often gather- 

 ing in loose woods, sometimes dotted singly, not un fre- 

 quently making, with many other small trees, regular 

 thickets drowned in the tall grass. Large deciduous 

 trees like the baobab, the ceiba, the tamarind, the 

 sycamore, or a banyan-like fig-tree prefer to stand 

 alone in the open. The guttifer shi-butter or butter- 

 and- tallow tree is also one of the economic features. 

 Palms of the borassus type and kernel oil-palms form 

 groves in the south, whereas the doum-palm prevails in 

 the north. The raphia wine-palm adorns the margins of 

 rivers and lakes. 



p 2 



