Vol. IV. 
JANUARY, 1917 
No. 1 
AMERICAN 
JOURNAL OF BOTANY 
OFFICIAL PUBLICATION OF THE 
BOTANICAL SOCIETY OF AMERICA 
CONTENTS 
The influence of certain climatic factors on the development of Endothia 
parasitica (Murr.) And.. Neil E. Stevens 1 
Gunnera petaloidea Gand., a remarkable plant of the Hawaiian Islands. 
Vaughan MacCatjghey 33 
An interesting modification in Xanthium .Charles A. S^ull 40 
Endophyllum-like rusts of Porto Rico E. W. Olive and H. H. Whetzel 44 
PUBLISHED 
IN COOPERATION WITH THE BOTANICAL SOCIETY OF AMERICA 
BY THE 
BROOKLYN BOTANIC GARDEN 
At 41 North Queen Street, Lancaster, Pa, 
Entered as second-class matter February 21, 1914, at the post office at Lancaster, Pennsylvania, 
under the act of March 3, 1879; 
