AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
EDITORIAL COMMITTEE 
F. C. Newcombe, Editor-in-Chief 
University of Michigan 
C. Stuart Gager, Business Manager R. A. Harper, 
Brooklyn Botanic Garden Columbia University 
Irving W. Bailey A. S. Hitchcock 
Bussey Institution Bureau of Plant Industry 
H. H. Bartlett Edgar W. Olive 
University of Michigan Brooklyn Botanic Garden 
A. G. Johnson, University of Wisconsin 
(Representing American Phytopathological Society) 
VOLUME IV 1917 
WITH THIRTY-ONE PLATES AND NINETY-FOUR TEXT FIGURES 
PUBLISHED — ^ 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At 41 North Queen Street, Lancaster, Pa. 
