LETTER OF TRANSMITTAL 



U. S, Department of Agriculture. 



Division of Agrostology, 

 Washington, D. C, May 19, 189S. 



Sir: I have the honor to transmit for your approval the manuscript 

 of a continuation of Studies on American Grasses, embracing (1) "A 

 revision of the North American species of Calamagi-ostis,'^ by Mr. 

 Thomas H. Kearney, jr., assistant agrostologist, and (2) "Descriptions 

 of new or little-known grasses," by the Agrostologist, and respectfully 

 recommend its publication as Bulletin No. 11 of this division. In the 

 paper on the revision of the genus Calamagrostis only those species 

 are included which occur in North America north of Mexico. All 

 enumerated are natives, and of the thirty-eight species described 

 thirty-three are believed to be endemic. Twenty-three species and 

 varieties are described as new. 



In the Rocky Mountain region there are twelve species, and while 

 none are found in the Gulf States excepting in northern Georgia, they 

 extend southward through Mexico, and the species multii)ly along 

 the Andes of South America. In his enumeration of the species of 

 Calamagrostis of the higher Andes Mr. H, L, Weddell characterizes 

 sixty species. In North America the species are most abundant on 

 the Pacitic sloi)e, where twenty-five species are known to occur. 



The new species are fully described, and the synonymy and distribu- 

 tion of all the species included is fully presented. The keys of analysis 

 have been made with much care, and can not fail to be found helpful 

 in determining the species. Some of the species present so many forms 

 that their limitation is difficult. In several cases it is impossible to 

 draw sharp lines of separation, and this is especially true of Calama- 

 grostis canadensis and Calamagrostis langsdorffli, also Calamagrostis 

 hyperborea and Calamagrostis inexpansa. The descriptions and the 

 data furnished relative to the distribution of the species are based 

 upon specimens contained in the United States National Herbarium, 

 and also those in the leading herbaria of the countiy. 



That it has been i^ossible to examine so large a series of specimens is 

 due to the courtesy of those in charge of the several collections sub- 

 mitted for the purpose. Expression of thanks is here tendered to ]\Ir. 

 James Macoun, of the Geological and Natural History Survey of 



