VIU PREFACE. 



Hooker, under the authority of the Home or of Colonial Governments 

 it is necessarily uniform in general plan with those which have been 

 already issued. 



"The principal features of this plan, as settled by Sir W. J. 

 Hooker, and described in his report, are these : — 



"1st. The descriptions are drawn up in the English language, 

 Mr. Bentham's ' Introduction to Botany, drawn up with special reference 

 to Local Floras,' containing the technical terms used in the descriptions, 

 being prefixed to the work. 



" 2nd. The general sequence of Natural Orders adopted is that of 

 the ' Prodromus ' of De Candolle, being that which experience has 

 shown to be practically the most convenient. In accordance with this 

 sequence, British Botanists are accustomed to arrange their Herbaria 

 and works of descriptive Botany. In the more detailed arrangement 

 of the genera, the ' Genera Plantarum ' of Messrs. Bentham and 

 Hooker has been followed, and a reference to that work is given with 

 each genus. 



" With regard to the synonymy of the species here described, while 

 the authors have endeavoured to quote all names which have been 

 applied to Tropical African plants, they have not, in the case of widely 

 diffused species, regarded it as either necessary or desirable to include 

 their whole synonymy, the reliable citation of which would have 

 involved very much more time, laboui-, and space than the end to be 

 attained would warrant ; besides that, it would be out of place in a 

 special work of this kind. Any new^ identifications of African with 

 extra-African species are, of course, recorded." 



In one particular, however, I have been obliged to depart slightly 

 from the plan of my predecessor. The last of the three published 

 volumes of the " Flora of Tropical Africa" appeared in 1877. Since 

 then our knowledge of the vegetation has increased very greatly. 

 Large tracts which were unexplored botanically at that date have 

 yielded numerous and copious collections. In resuming the \\ork, it 

 has therefore been found necessary to more clearly define the regions 

 into which Professor Oliver divided the whole area. In attempting 

 this, advantage has been taken as far as possible of political boundaries, 

 since they admit of easy recognition. The regions may now be briefly 

 defined as follows : 



1. Upper Guinea. — The Western Coast region from the mouth 

 of the Senegal Biver to the southern boundary of the Cameroons. It 

 contains practically the whole of the Niger Basin. It is bounded 

 on the noith by a line stretching from the mouth of the Senegal 

 River to Lake Chad ; on the east by the 15th meridian of East 

 longitude to its intersection with the southern boundary of the 

 Cameroons, which bounds it to the south. It includes also the island 

 of Fernando Po. 



2. North Central. — This includes the Sahara. It is bounded to 

 the north by the Tropic of Cancer ; on the west by the Atlantic ; on the 

 east by the 26th meridian of East longitude ; on the south by the Upper 

 Guinea region and the Congo Free State. 



