UC-NRLF 



- 



UNITED STATES DEPARTMENT 0F 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 

 Scope and Plan of the Work ..... 1 



Poaceae, the Grass Family ...... 5 



Descriptions of the Subfamilies and Keys 



to the Tribes .......... 6 



Descriptions of the Tribes and Keys to 



the Genera ........... 



Descriptions of the Genera 



1. Bamboseae, the Bamboo Tribe 



2. Festuceae, the Fescue Tribe . 



3. Hordeae, the Barley Tribe .. 



4. Aveneae, the Oat Tribe ..... 106 



5. Agrostideae, the Timothy Tribe . . 121 



6. Nazieae ^he Curly-Mesquite Tribr 165 



Paeg 

 Descriptions of the Genera Continued. 



7. Chlorideae, the Grama Tribe ... 171 



8. Phalarideae, the Canary-Grass Tribe 199 

 9: Oryzeae, the Rice Tribe 204 



10. Zizanieae, the Indian-Rice Tribe . 206 



11. Melinideae, the Molasses - Grass 



Tribe 212 



12. Paniceae, the Millet Tribe . . . .213 



13. Andropogoneae, the Sorghum Tribe 252 



14. Tripsaceae, the Corn Tribe .... 280 

 List of New Species and New Names . .288 

 Index 289 



WASHINGTON 



GOVERNMENT PRINTING OFFICE 



1920 



