THE GRAMA GRASSES: 
BOUTELOUA AND RELATED GENERA. 
By Davip GrirrFirus. 
INTRODUCTION. 
BASIS AND METHODS OF THE WORK. 
It was during the writer’s connection with the University of Arizona 
in 1900 that work was begun on this group of plants. Preparations 
were then made to grow the plants under cultivation at the University 
in a region where the species predominate in the grass flora and form 
the main feed upon public and private stock ranges. A change of 
location caused a change of the plan of work. Since 1901 the writer’s 
studies in the field have been carried on during extensive travel 
on behalf of the Department of Agriculture for the study of the public 
stock ranges and other purposes. In addition, travel has been per- 
formed extensively in Mexico under conditions which have allowed 
good opportunity for study. 
The material in the following herbaria has been examined: United 
States National Herbarium, Gray Herbarium, herbarium of the Mis- 
souri Botanical Garden, herbarium of the Field Museum of Natural 
History, herbarium of the California Academy of Sciences (before 
the fire), and the private herbaria of Brandegee and Tracy. But 
while the collections in these herbaria were studied, the work is based 
mainly upon the material in the United States National Herbarium, 
and the specimens listed are almost entirely from that repository. 
During his visit to Europe in 1907, Prof. A. S. Hitchcock secured, 
through the kindness of the directors of the herbaria there, fragments 
of several typical or authentic specimens for deposit in the National 
Herbarium. In other cases he procured photographs of type speci- 
mens and made notes and drawings that have greatly aided in the 
interpretation of the older names of the species. Further information 
has been obtained through correspondence with the directors of the 
botanical gardens at Kew and Berlin, to whom acknowledgments 
are due for their courtesy. 
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