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LETTER OF TRANSMITTAL. 



U. S. Department of Agriculture, 



Division of Agrostology, 

 Washington, T). C, April 8, 1899, 



Sir : I liave the honor to transmit herewith the manu- 

 script and illustrations for "American Grasses II," and 

 recommend its publication as Bulletin Xo. 17 of this 

 Division. "American Grasses I'' was published as 

 Bulletin Xo. 7, and contained illustrations of 302 species. 

 In this second part 325 additional species are described 

 and illustrated, making a total of 627 species. Many of 

 our grasses are here illustrated for the first time, and 

 as a whole it is believed that the work will be helpful 

 to students of grasses in determining the species of this 

 most important family of plants. In the preparation of 

 this part more attention has been given to synonymy 

 and to the citation of authorities, and the descriptions 

 have been extended in order to facilitate identification. 



Of the species now illustrated, 19 may be regarded as 

 characteristic of the Atlantic Coast region, 83 to the 

 region of the Gnlf of Mexico, 92 to the Southwest, in- 

 cluding the States of Texas, Xew Mexico, Arizona, and 

 southern California, 74 to the States of California, Ore- 

 gon, and Washington, and 01 to the Kocky Mountain 

 region, of which 19 may be regarded as more properly 

 the prairie species of that region. The distribution (f 

 some of the species is very limited, while that of others 



