"222 Transactions of the South African Philosophical Society. 



OncHiDACEiE, Ericaceze, Eestionace^, Ficoide^, Geraniace^, and 

 Proteace^ that the chief distinctive characters of the Peninsular 

 Flora, taken as a whole, will be found. To these may be added, as 

 a character of secondary importance, the presence of a considerable 

 number of genera rich in species, of which some details will be now 

 adduced. 



The 2,117 species of native flowering plants enumerated in the 

 " List " belong to 93 Orders and 485 genera. The average number 

 of species to each genus is therefore 4-36.''' This, from a comparison 

 with other Floras of a similar size, is somewhat high, and seems to 

 stand in opposition to the greatly diversified character which has 

 been noted by previous writers as one of the most marked features of 

 the South African Flora generally. It appears, however, to be 

 chiefly due to the presence of a few genera very numerous in species. 

 This is shown by the following list of the largest genera : — 



Species, 



Erica 92 



Mesembrianthemum 61 



Aspalathus 50 



Disa 47 



Senecio 40 



Ficinia 36 



Oxalis 32 



Pelargonium 30 



Crassula 29 



Helichrysum 29 



Eestio 29 



Gladiolus 24 



499 



We have, therefore, the first four genera with 250 species, or 

 very nearly 12 per cent, of the whole ; and twelve genera with 

 499 species, or 23*59 per cent, of the whole native Flora. 



Most of these large genera are either exclusively South African 

 or genera having their largest or at least a very large development in 

 South Africa, the cosmopolitan Senecio being the only exception. 

 But it is even more significant that, with two exceptions {Mesem- 

 brianthemum crystallinum and Senecio vulgaris), all the Peninsular 

 species of these large genera are, so far as I have been able to 



* In Mr. Wood's Catalogue of the Flora of Natal (a very much larger area) the 

 average is 3-12 species to each genus. 



