THE PLANT WORLD 



A Monthly Journal of General Botany 



Established 1897 



Edited by 

 FORREST SHREVE 



Published by 

 THE PLANT WORLD ASSOCIATION 



Volume 21 



OFFICE OF PUBLICATION 



2419-21 Greenmount Ave. 



baltimore, md. 



EDITORIAL OFFICE 



TUCSON, ARIZONA 



1918 



