80 



NORTE AMERICA 



a coastal fringe, to the Arctic islands, and reaches a great 

 development in western Greenland. 



The specific feature of the American tundra, as com- 

 pared with those of Siberia and Greenland, is the 



Fig. 23. Vegetation of North America. 



wealth and extent of its lichen carpets ; the cold desert 

 seems to be drier here than in Europe and Asia. 

 Though the ling heath is entirely absent from America, 



