J.D.S. 



LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Division of Agrostology, 

 Washington, D. 0., January 1°2, 1900. 

 Sir: I transmit herewith and recommend for publi- 

 cation descriptions and analytical keys of the tribes 

 and genera of North American Grasses. Each genus 

 is illustrated, and reference is made to all other species 

 of the genus illustrated in Bulletins Nos. 7 and 17 of 

 this Division. There is added a bibliograplry of all the 

 authors cited in these bulletins. This bibliography will 

 be of great assistance to the working student, and the 

 analytical keys will be helpful in identifying our Amer- 

 ican Grasses. 



A portion of the matter here offered was published 

 in the introduction to Bulletin No. 7, and although it 

 may still serve as an introduction to the study of Amer- 

 ican Grasses it has been deemed best to issue it in its 

 present expanded form as a separate publication. It 

 is in a measure complete in itself, and will be as useful 

 to those who have already received Bulletins Nos. 7 

 and 17 as to those who may receive copies of future 

 editions of American Grasses, Illustrated. 

 Respectfully, 



F. Lamson-Scribner, 



Agrostologist. 

 Hon. James Wilson, 



Secretary of Agriculture. 



