Chapter V 



-87- 



T3rpes of Areas 



characteristic fact that in western Africa we find a large number of 

 species of tropical India; in eastern Africa, on the other hand, we find 

 the predominance of more widely distributed species, resembling 

 Mediterranean forms. As examples of this type we may cite the areas 

 of the following genera: Ancistrocladus , Sesamum, Citrullus, Podocarpus, 

 Pandanus, Borassus, Musa, Olea, Cojfea, Luffa, Lagenaria, Momordica, 

 Anisophyllea, Hypericum [H. niycorens). 



h. Africa-Madagascar Type. — In the case of this and the following 

 type we understand under "Madagascar" not only Madagascar proper 

 but also the adjacent group of islands (Reunion, Mauritius, Seychelles). 

 As an example of this type of area we may cite Viola abyssinica, found 

 in Abyssinia and the Cameroons and then on Madagascar and adjacent 



Fig. 14. — Mediterranean-North American discontinuous areas: 6, Platanus orientalis 

 (Mediterranean), P. occidentalis (North American); 7, Cercis Sitiquaslrum (Mediterranean), 

 C. canadensis (North American); 8, Comandra elegans (European) and Comandra umbellata 

 (North American). (After Fernald). 



islands (here represented by a vicarious or perhaps even identical 

 species, V. emirnensis). Geranium simense, Senecio Bojeri, and others 

 have similar areas. 



c. Asia-Madagascar Type. — ^Among genera distributed both on 

 Madagascar and in Asia (India), extending sometimes also to Australia 

 and PoljTiesia, we may mention Nepenthes, Wormia, and Pathos. 



In addition, there are a number of species and genera growing in 

 Madagascar that are found also both in Africa and India, e.g., Buddleia 

 madagascariensis. 



d. Africa-America Type. — The tropics of Africa and America are 

 characterized by a number of genera found only on these two continents 



