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, L. R. Jones, 
University of Chicago University of Wisccnsit-. 
C. Stuart Gager, Business Manager Orland E. White, 
Brooklyn Botanic Garden Brooklyn Botanic Garden 
R. A. Harper, Jacob R. Schramm, ^^bf\\\\ 
Columbia University Cornell Universf^ 
C, L. Shear, Bureau of Plant Industry 
(Representing American Phytopathological Society) j ^ ^ ^ ^ ^ 
VOLUME VII 1920 
WITH THIRTY-FIVE PLATES AND ONE HUNDRED AND SEVENTY TEXT FIGURES 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At 41 North Queen Street, Lancaster, Pa. 
