1893 FLORAL REGIONS IN AFRICA. 373 



tion, and the conditions vary so greatly that in this peninsula there 

 are probably more species than exist anywhere in the world on a 

 similar area. 



This makes, therefore, in Southern Extratropical Africa, four 

 distinct floras, all, probably, closely united genealogically, but all 

 speciiically and very often generically distinct. 



Turning now to Tropical Africa, a glance at the map and the 

 exercise of the imagination will show that the enormous valleys of 

 the Congo and Niger, up to from 3,000 to 5,000 feet, have been exca- 

 vated out of a continuous tableland, and are in free communication 

 with each other by the littoral of the west coast. Speaking gene- 

 rally, the whole of this enormous region is one continuous, dense, 

 evergreen forest, and similar humid conditions prevail throughout its 

 whole area. It, therefore, forms another Hora comparable with the 

 others and probably not nearly so much richer as might be supposed. 

 The higher lands above 3,000 feet at 10^ N. lat., and above 5,000- 

 7,000 feet at the Equator, have another flora of a more or less similar 

 type to that of Abyssinia, and the truly alpine flora of the Cameroons, 

 for instance, seems almost specifically the same. In this region one 

 can never see the landscape, as one walks usually through hedges of 

 trees and shrubs 30 to 70 feet in height, or when the forest has been 

 cleared, through tall grass which gives a realistic idea of the pre- 

 sumable view of a rabbit in a field of corn. 



Hence, to show the relative abundance of floral regions, we have 

 in North Extratropical Africa the South European flora in Morocco 

 and Algiers, the Sahara desert flora, the Syrian flora at Alexandria, 

 and the Egyptian or Delta flora, while in Southern Extratropical 

 Africa there are temperate forest floras in Natal and the Cape, a 

 grassy plateaux flora in the Transvaal and Cape Colony, the Karoo 

 desert flora, and that of the Cape proper ; that is to say, eight different 

 sets of climatic conditions. In Tropical Africa there are the evergreen 

 forest and the plateaux flora, that is to say, only two, of which the 

 second is practically the same as that of the Transvaal, or is, at any 

 rate, so close as to be scarcely reckoned as distinct. If one takes in 

 the alpine flora of the highest summits of the Atlas, Abyssinia and 

 Kilima-njaro, we get a total of eleven different floras. 



The manner in which these have so far been studied reveals the 

 difficulties of systematic botany. Boissier's " Flora Orientalis '' mixes 

 up part of the Algerian, part of the Sahara and part of the Syrian and 

 Egyptian floras. Oliver's "Flora of Tropical Africa" includes, 

 the tropical forest, the Abyssinian and Transvaal grassy plateaux, 

 and the alpine plants in part, and is about half done. Harvey and 

 Sender's " Flora Capensis " mixes inextricably the grassy plains of 

 the Transvaal, the Karoo, and the peninsula, and is not half finished. 

 Engler's " Hochgebirgeflora," containing the high mountain plants, 

 is the only attempt to work on natural lines, and is also pre-eminently 

 distinguished from the last two by having reached a conclusion. 



G. F. Scott Elliot. 



