PREFACE v 



cation has been employed with a few slight modifications. The sequence in 

 the text is from buttercups to mints, then from roses to asters, and from 

 arrowheads to orchids and grasses. The pines are placed at the end and 

 quite frankly out of their proper position for reasons of convenience. 



The color illustrations have been made in the field with few excep- 

 tions. The line drawings are largely from herbarium material. In both 

 cases, drawings have been made natural size throughout, except in case 

 of small parts such as fruits, spikelets, perigynia, etc. 



The range of the book is essentially that of Coulter-Nelson's "Man- 

 ual," namely, Colorado, Wyoming, most of Montana, Northern New Mex- 

 ico, Eastern Utah, and Western North and South Dakota, Nebraska and 

 Kansas. The layman will find the book useful over a much wider area , 

 since the majority of the species in color occur from the Canadian Rockies 

 to California or Arizona. 



Frederic E. Clements, 

 Edith S. Clements. 

 Minnehaha-on-Ruxton, 

 Manitou, Colorado, 

 Tulv 22, 1913. 



