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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. 
C. Stuart Gager, Business Manager 
Brooklyn Botanic Garden 
R. A. Harper, 
Columbia University 
C. L. Shear, Bureau of Plant Industry 
H. H. Bartlett, 
University of Michigan 
Arthur H. Graves, 
Brooklyn Botanic Garden 
I. F. Lewis, 
University of Virginia 
(Representing American Phytopathological Society) 
VOLUME lX-1922 
WITH THLRTY-FIVE PLATES AND ONE HUNDRED AND FOURTE|;gg^^ I^i'^^[J]^J^S^ 
PUBLISHED 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At Prince and Lemon Streets, Lancaster, Pa. 
