UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 772 
Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
Washington, D. C. PROFESSIONAL PAPER | March 20, 1920 
THE GENERA OF GRASSES OF THE 
UNITED STATES 
WITH SPECIAL REFERENCE TO THE ECONOMIC SPECIES 
By 
A. S. HITCHCOCK, Systematic Agrostologist 
CONTENTS 
; Page Paez 
Scope and Plan ofthe Work . .. -. . 1 | Descriptions of the Genera—Continued. 
Poaceae, the Grass Family. . .... 5 7. Chlorideae, the Grama Tribe . . . 171 
Descriptions of the Subfamilies and Keys 8. Phalarideae, the Canary-GrassTribe 139 
ee OS s\2 nie) cause 28 9. Oryzeae, the Rice Tribe. . . » . 204 
Descriptions of the Tribes and Keys to 10. Zizanieae, the Indian-Rice Tribe . 206 
MEREIDED: i's. or © eho et wt ae raee 
Descriptions of theGenera . (.. . . Ii. Melinideae, the Molasses - Grass 
TSIEN sy entehcaeente taint leh ter ema 
1. Bamboseaé, the Bamboo Tribe .. é i 
2. Festuceae, the Fescue Tribe . . . 12. Paniceae, the Millet Tribe . . . . 213 
3. Hordeae, the Barley Tribe . . r 13. Andropogoneae, the Sorghum Tribe 252 
4. Aveneae, the Oat Tribe. . ... 14. Tripsaceae, the Corn Tribe. . . «. 280 
6. Agrostideae, the Timothy Tribe . List of New Species and New Names . . 288 
6. Nazieae, the Curly-Mesquite Tribe . 165 | Index . . » « « » 0 © © © © «© 0 20d 
WASHINGTON 
GOVERNMENT PRINTING OFFICH 
. 1920 
