PREFACE vii 



which name it can he designated for a definite term of years, with 

 provision for revising and correcting the Hst at probably five- 

 or ten-year intervals, after due notice to all concerned. 



In this catalogue it should be noted that this necessary arbi- 

 trary agreement upon a name does not imply criticism of any bo- 

 tanical authority. The Committee has been at the greatest pains to 

 inform itself concerning the usage of the best authorities, and it 

 has in most cases followed the usage of such authorities. In a 

 few cases, and for reasons deemed adequate, deliberate departure 

 from such usage has occurred. It should be noted that two 

 codes of botanical nomenclature are in use among botanists— the 

 American Code and the International, or Vienna, Code. 



Official Code of 1917. In the winter of 1915-1916 the Commit- 

 tee took advantage of an opportunity afforded by the publication 

 of the sixth volume of the Standard Cyclopedia of Horticulture, 

 in which Dr. L. H. Bailey, its editor, included a Finding List of 

 Latin or Latinized binomials commonly used in North American 

 literature and commerce, with their equivalents in the Cyclopedia. 

 The Committee was permitted, through the courtesy of Dr. 

 Bailey, to insert in this list ''stars" to indicate the names recom- 

 mended by the Committee as the standard names for use in 

 the horticultural trades for a considerable number of plants, 

 mainly trees and shrubs. A reprint of the hst as it appeared in 

 the Cyclopedia was distributed as the 1917 Official Code of 

 Standardized Plant Names, and has been extensively adopted 

 and used. It is now superseded by this work, which records in the 

 slight changes that may be observed the orderly progress of name 

 revision above referred to. 



Subsequent Work. The matter rested during the war, but in 

 1919 the Committee took up its work seriously, and after much 

 labor and many delays due to the constant enlargements in scope 

 and the ramifications of the subject, it has brought this work to 

 the point of the present publication, which contains not only a 

 vastly increased list of scientific names, including herbaceous as 

 well as woody species, but also their approved common names, and 

 the approved names of great numbers of horticultural varieties. 



Horticultural Necessity and Convenience Paramount. What the 

 Committee seeks to do is not to hamper the progressive correction 

 and improvement of botanical nomenclature, and least of all the 

 freedom of research, publication, and discussion among taxo- 

 nomic botanists; but rather to provide a convenient and prac- 



