BOTANICAL GEOGRAPHY 



329 



in the equatorial Andes and lessens in higher latitudes as 

 one goes either way from the equator. In the White 

 Mountains, for instance, the timber line only rises to about 

 four thousand five hundred feet. The seed-plants of alpine 

 regions in all parts of the earth have a peculiar and charac- 

 teristic appearance. It is easiest to show how such plants 

 differ from those of the same species as they look when 



FIG. 233. Trees near the Timber Line on the Slope of Pikes Peak. 



growing in ordinary situations by reference to the plants 

 themselves or to good pictures of them (see Fig. 285). 

 The differences between alpine and non-alpine plants of 

 the same or closely related species have been summed up 

 as follows : l 



"The alpine individuals have shorter stems, smaller leaves, 

 more strongly developed roots, equally large or somewhat 

 larger and usually somewhat more deeply colored flowers, 

 and their whole structure is drought-loving (xerophilous)." 



i By A. F. W. Schimper. 



