2 PREFACE 



Especial acknowledgments are due to Professor Benjamin 

 L. Robinson, Director of the Gray Herbarium of Harvard 

 University, who has given most valuable advice and has 

 revised the manuscript of the keys and flora-, thus contribut- 

 ing greatly to any value which they may be found to possess. 



Much aid has been derived from the careful proof-reading 

 of Professor J. M. Holzinger of the Minnesota State Normal 

 School, Professor L. H. Pammel of the Iowa State College, 

 and Miss Mary P. Anderson of the Somerville, Mass., English 

 High School. The author wishes heartily to thank these 

 critics for the many errors which they have corrected and 

 the valuable additions which they have suggested. 



The territory covered overlaps that dealt with by Professor 

 Tracy in the flora above cited, and nearly meets that embraced 

 in Miss Eastwood's Flora of the Rocky Mountains and the 

 Salt Lake Basin, since many of the species treated in the 

 present work range west as far as the hundredth meridian. 



The plants chosen to constitute this flora are those which 

 bloom during some part of the latter half of the ordinary 

 school year, and which liave a rather wide territorial range. 

 Enough forms have been described to afford ample drill in 

 the determination of species. Gray's 3Ianual of Botany or 

 Field, Forest, and Garden Botany will of course be employed 

 by the student who wishes to become familiar with most of 

 the seed-plants of the region here touched upon. Those 

 species which occur in the central and northeastern United 

 States only as cultivated plants are so designated. The illus- 

 trations are mainly redrawn from German sources. A few 

 of them are the work of Mr. E. N. Eischer of Boston, but 

 the greater portion are by Dr. J. W. Folsom of the Illinois 



Industrial University. 



J. Y. B. 



Cambridge, Mass., January, 1901. 



