VI PREFACE 



To others who have also helped by the collection of specimens, 

 notes and other information, the writer is glad to make acknowl- 

 edgments. Among those who have helped in various ways are: 

 Professor M. L. Fernald, Stewardson Brown, Bayard Long, 

 Dr. Witmer Stone, Miss F. A. Mulford, Harold W. Pretz, Dr. 

 F. W. Pennell, Dr. Roland M. Harper, Dr. Philip Dowell, and 

 Dr. G. E. Nichols. To Dr. Arthur Hollick the writer is under 

 great obligations for much aid in the considerable geological data 

 used in the book. He is also indebted to Mr. Sereno Stetson for 

 making the original base map which has been used in a number of 

 ways in the book. Several genera and families, and a bibliography, 

 have been contributed by specialists and such contributions are 

 noted in the text. Mr. Percy Wilson, of the New York Botanical 

 Garden, has kindly aided in the determination of many specimens, 

 and in other ways. 



In order to base the book on a descriptive illustrated work, the 

 taxonomy and nomenclature have been brought into substantial 

 accord with the second edition of "Illustrated Flora of the Nor- 

 thern States and Canada," which was published about the time 

 the manuscript of the present book was completed, and to which 

 reference is made for additional synonyms. This does not imply, 

 however, that the writer favors all the generic and specific de- 

 limitations of that work, nor all the nomenclatorial changes there 

 proposed. 



The interest of Dr. N. L. Britton has been continued until the 



completion of the work, and the author takes great pleasure in 



acknowledging his help and valued criticism, without which the 



book could scarcely have been written. 



Norman Taylor. 



Brooklyn Botanic Garden, 

 30 July, 1914. 



