INTRODUCTION. 13 



names; so that the reader who prefers to maintain the current; 

 though not-to-be-recommended attitude, will "have no difficulty 

 in choosing a name to suit his taste, or, if he desires, he may 

 establish a name of his own." Preference has always been 

 given, by the writer, to the oldest unpreempted specific name 

 and the date of publishing has been determined in every case 

 with as much accuracy as possible. For all names printed, 

 the author, page-number of work and date of publication have 

 been cited and an effort has been made to procure exact biblio- 

 graphic detail so far as conditions would permit. Biblio- 

 graphic works, such as those of Pritzel (9) and Jackson 

 (10), have been of much assistance in determining publica- 

 tion dates of many obscure and inaccessible works while 

 the libraries of the Department of Botany and the Survey, 

 at Minneapolis have been serviceable. In addition, the full 

 collection of books belonging to the University of Nebraska, 

 and the personal library of Dr. Chas. E. Bessey were put at 

 my disposal, and through this courtesy many references that 

 could not otherwise have been verified were critically exam 

 ined. Furthermore, under the direction of Dr. N. L. Britton 

 and Dr. Thos. Morong, bibliographic work on some 250 refer- 

 ences which had proved puzzling was conducted for me in the 

 libraries of Columbia college and in New York. By this kind- 

 ness many gaps have been filled. The Linnaean citations have 

 been worked out with the aid of Richter's well-known work 

 (11) and re visional assistance has been derived from the notes, 

 in Hitchcock's Ames Flora (12) and the chapters in Kuntze (13). 

 Besides these a large number of minor aids have been received 

 from numerous sources. I believe full credit is given under 

 each head in the general list, for all sources of information 

 drawn upon. 



Synonymy and orthography. It is not pretended that a com- 

 plete synonymy is given in any case, although it has been the 

 endeavor to make it as complete as possible. In the old divi- 

 sion Polypetalae, use has been made of the remarkably exact 

 and painstaking bibliographic index prepared by the lamented 

 Sereno Watson (14); in the Gamopetalae the laborious compila- 

 tions found in Gray's Synoptical Flora (15) have been, in niost 



(9) Pritzel: Thes. Bot. Lit. ed. I. (1851.) 



(10) Jackson: Guide Lit. Bot. (1881.) 

 (11). Klchter: Codex Linnaeus (1835). 



(12). Hitchcock: Fl. Ames, Trans. St, Louis Acad. Sci. (1891). 



(13). Kuntze, Revisio Generum Plantarum, Vol. I, introd. CXXll—CXLYl. (1891). 



(14). Watson: Bihliographic Ind. N. Amer. Bot. Pt. I (1878). 



(15) Gray: Syn. Fl. U. S. (1886). 



