BOOKS AND CURRENT LITERATURE 



A Flora of the Rocky Mountains. — A manual of the Colorado 

 mountain flora has just been published by Prof. Frederic E. Clements 

 and Dr. Edith S. Clements.^ The book is designed to be a particu- 

 larly useful one to the amateur who wishes to become acquainted 

 with the plants of the Rocky Mountains. It is furnished with keys, 

 and a large number of characteristic plants are illustrated in color, 

 from the brush of the junior author. There are no descriptions of 

 the species, no synonymy is given, and there are no localities nor state- 

 ments as to habitat and range, all of which are features that will limit 

 the usefulness of the book. 



Rocky Mountain Flowers is of particular interest to botanists by 

 reason of the fact that it is written, as the authors state, ''from the 

 standpoint of the experimental ecologist," being "concerned primarily 

 with the relationships of 'species' and their subdivisions as an organic 

 expression or measure of habitat differences, and of the competitive 

 relations of the various formations," 



A tangible evidence of the viewpoint from which the flora has been 

 elaborated consists in the greatly reduced number of species which 

 it enumerates as compared with other works covering the same terri- 

 tory. Rydberg credits 2872 species of flowering plants to Colorado; 

 Nelson describes 2689 species for Wyoming, Colorado and adjacent 

 portions of the neighboring states, while Clements and Clements em- 

 brace only 1878 forms in Rocky Mountain Flowers. This is to say 

 that 25 per cent of the species in Rydbei'g's Flora of Colorado are 

 omitted from the work mider notice. The authors state in their preface 

 that they have omitted many of the recent segregates from long-known 

 species, and that the.y have done so on the evidence of experimenta- 

 tion and field study which have demonstrated that the groups of closely 

 related segregates are expressions of habitat effects upon a single specific 

 stock. The authors have thus reduced their presentation to "units 



1 Clements, Frederic E., and Clements, Edith S. Rocky Mountain Flowers: 

 An Illustrated Guide for Plant-lovers and Plant-users. 392 pp., 47 pis. The 

 H. W. Wilson Company, \^ hite Plains, N. Y. 1914. 



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