KEY 



TO THE 



ROCKY MOUNTAIN FLORA 



COLORADO, UTAH, WYOMING, IDAHO, 



MONTANA, SASKATCHEWAN, 



ALBERTA, 



AND PARTS OF 



NEBRASKA, SOUTH DAKOTA, NORTH 

 DAKOTA, AND BRITISH COLUMBIA 



BY 



P. A. RYDCERG, Ph.D. 



Curator, New York Botanical Garden 



NEW fORK 



"I'ublicLed by tho Author 



1919 



