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 
specifically 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 flora 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 
Sonder’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. EB. Scorr Errron. 
