into several geographical species and does not give exact limits 

 of their ranges. How can a botanist without access to all or 

 most of the larger herbaria know if he is to include or exclude 

 the original species, if he has not authentic material himself? 

 The " Flora of Northwest America" therefore happens to con- 

 tain several species not growing within a thousand miles of the 

 region covered, i. c, as far as can be judged from specimens 

 in the collections of the New York Botanical Garden and Colum- 

 bia University. Such species are, for instance Scropluilaria Mar- 

 ilatidica and Polygoimni crcctiun, not found west of Nebraska ; 

 Eriogonnin corynibosuin and GrapJicphoniui Wolfii, not north of 

 Colorado ; Salix saxiinontana and Gcranhan Frcniontii, not north 

 or west of Wyoming ; Toficldia glntiiiosa, Poa glaiica and P. 

 laxa, only found in the northeastern part of the continent. 



With regard to nomenclature, ^Ir. Howell has been progres- 

 sive, following the Rochester Code with slight modification and 

 using in most cases the generic names adopted in the second edi- 

 tion of Heller's Catalogue. As to the limitation of genera he has 

 been somewhat radical, adopting most of the segregations made 

 in later years. As to the limitation of species he has on the 

 contrary been rather conservative, ignoring many of the newer 

 finer splits and proposing very few new ones himself. Those 

 that he has proposed are well founded. He has admitted very 

 few varieties. Those that he has admitted were probably not 

 well known to him. In most cases he has raised the varieties to 

 species if they could be well recognized ; if not they have been 

 ignored. 



Whatever smaller defects the work may have, it will be of 

 great value to the student of the botany of the Columbia Valley 

 region. It will be for that region what Chapman's Flora has 

 been for the South, Coulter's Manual for the Rockies and tlie 

 Botany of California for the southern portion of the Pacific Slope. 

 We need now a flora of the southwestern United States and the 

 Great Basin. 



I'. .\. Rvni'iERG. 



