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. RYDBERG, Ph.D. 



Curator, New York Botanical Garden 



NEW YORK 



Published by the Author 



1919 



r 



