Geographic Distribution of Animals and Plants 599 



V. REGIONS OF GEOGRAPHIC DISTRIBUTION OF 

 VEGETATION OF NORTH AMERICA 



If a study were made of the geographic distribution of plants through- 

 out the worldj we would find that the world could be divided into geo- 

 graphic regions (just as for animals), each with its particular environ- 

 mental characteristics and peculiar flora. However, it may be just as 



Fig. 312. — Vegetation areas of North America (the boundaries of the various 



regions are given in a general way). 



interesting and profitable to limit our study of phytogeography to North 

 America. It will be observed (Fig. 312) that the North American con- 

 tinent can be divided into various vegetation areas (geographic regions). 

 These areas are summarized in an accompanying table in which the gen- 

 eral environmental characteristics and the plants typically present in 

 each region are given. Observe that the environmental characteristics 



