Preface. 



All the territory of the United States of America south of the 

 Britihs- boundary, except Oregon Washinpton and Idaho, being 

 supplied with local P'loras this work is intended to fill up the 

 earner left out by other authors. 



As the writing of descriptions of plants at this late date is, to 

 a great extent, writing or copying what others have previously 

 done, it is hardly right to claim originality for work done in that 

 field; I. therefore, wish to acknowlege that I have used the works 

 of Torrey & Gra\-, Dr. Asa Gray, Sereno Watson, William 

 Trelease, Coulter & Rose, Edward L. Greene and others, and to 

 save repetition (which would otherwise occur on every page) 

 I wish to give full credit here tr< all authors, any portion of 

 whose works have been copied herein. 



Wherever possible descriptions have been drawn from speci- 

 meiis in hand, but some I have been unable to procure and for 

 these I have had no other alternative than to copy from descrip- 

 tions already published. 



Believing that if a plant has one constant character that is 

 different from any of its cogeners it is sufficient for a species; and 

 that if a plant is sufficiently distinct from others to deserve a 

 name it is better to have it described as a distinct species than 

 as a variety of some other species, I have therefore, raised 

 nearly alL published varieties of the region embraced in this work 

 to specific rank. ^ 



