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AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
EDITORIAL COMMITTEE 
C. E. Allen, Editor-in-Chief 
University of Wisconsin 
William Crocker, 
The Thompson Institute For Plant Research, Inc. 
H. H. Bartlett, 
University of Michigan 
C. Stuart Gager, Business Manager 
Brooklyn Botanic Garden 
Arthur H. Graves, 
Brooklyn Botanic Garden 
R. A. Harper, 
Columbia University 
I. F. Lewis, 
University of Virginia 
Donald Reddick, Cornell University 
(Representing American Phytopathological Society) 
3 
VOLUME X—1923 
WITH THIRTY-NINE PLATES AND FIFTY-NINE TEXT FIGURES 
2At3 <o 0/ 
PUBLISHED 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At Prince and Lemon Streets, Lancaster, Pa. 
