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OUTLINE OF PLANT GEOGRAPHY 



originally Mexican politically, belong botanically to the northern 

 Mexican botanical province. The flora of this region is a typical 



Fig. 48. — Desert vegetation, Arizona. Nolina sp., Yucca sp. 

 Photo., Dr. W. S. Cooper. 





Fiq. 49. Mountain forest, Arizona. Photo., Dr. W. S. Cooper, 



xerophytic one, and is very rich in species, mostly belonging to 

 strictly American genera; indeed as a whole, this flora is perhaps 

 the most exclusively American of any region. First in importance 



