NOTES ON SOME WESTERN WILLOWS.* 

 Carleton R. Ball. 



The notes presented here are the partial results of several 

 months' study of western species of Salix. A systematic and 

 comparative study was made of over 30 species and their 

 numerous varieties. Less than half of them are considered in 

 the present paper. There are several exclusively western 

 species which, while perhaps not rare, are yet very imper- 

 fectly known, and there are two or three that are of extremely 

 local occurrence. There are also many species of considerable 

 abundance in higher latitudes, the limits of whose extension 

 into the United States are by no means definitely settled. 

 These are some of the questions for future investigation. 



The specimens on which this paper is based are those con- 

 tained in the herbaria of the Missouri Botanical Garden, the 

 Parry herbarium of the Iowa Agricultural College, and the 

 recent western collections of Prof. L. H. Pammel, of the last 

 named institution. To the Director of the Garden, Dr. Tre- 

 lease, and his assistants, and to Prof. Pammel, I desire to 

 express my gratitude for the many facilities placed at my 

 disposal and for numerous other acts of kindly assistance. 



It is thought that the synonymy of the species will be 

 found nearly complete, especially with regard to all recent 

 names, and that the bibliographic references will direct the 

 reader to the principal sources of information concerning each 

 species. In the list of specimens examined only such are cited 

 as have probably been distributed to one or more other her- 

 baria. Miscellaneous individual collections are not cited 

 unless they have been mentioned in the text. In the citation 

 of a specimen a long dash ( ) indicates that it was dis- 

 tributed unnamed ; an italicized Latin name indicates that it. 



♦ Presented in abstract to The Academy of Science of St. Loais^ April 17^ 

 1899. 



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