The Vegetation of North America 



337 



widely distributed lodgepole pine. In Colorado the limber pine, 

 and farther north in Montana the mountain pine, are locally 

 abundant, as is also the Douglas fir. 



In southern Colorado the yellow pine gives way to the nut pines 

 and junipers in semi-arid places. The forests on the plateau of 

 Arizona, and those above 5000 feet on the mountains of Arizona, 

 New Mexico, and western Texas, are dominated by yellow pine 

 bordered by belts of nut pine, juniper, and scrub oak at the semi- 

 arid lower levels. Usually there are belts of grassland and sage- 

 brush in the transition to the desert. 



At higher altitudes and in the moist canyons of Colorado, 

 Engelmann spruce and subalpine fir are abundant ; farther north, 

 firs. Western hemlock, and larch constitute important forest 

 types. Grasses, composites, and legumes furnish the bulk of 



t/ . 6 . 7* orest bervtce 



Fig. 209. Desert scrub near the east end of the San Bernardino Mountains, CaUfornia. 



