PEEFACE 



This flora furnishes a key to the commoner spring-flower- 

 ing families of Plianerogams and descriptions of the charac- 

 teristics of these families, together with such genera and 

 species under each as seem most available for school study in 

 the central and northeastern states. The descriptions have 

 been in part compiled by the author from various sources, 

 and in part written with the plants themselves in hand. The 

 characterizations of many families and of some genera are 

 taken with slight simplifications from Hooker's Student^ s 

 Flora of the British Islands ; a few are from Warming's 

 Systematic Botany. The remainder are mostly adapted from 

 the floras of Gray and Wood, from Sargent's Silva of North 

 America, and from Britton and Brown's illustrated Flora of 

 the Northern States and Canada. 



The sequence of the families (and sometimes the genera 

 under their respective families) is based on Engler's Syllabus 

 der Pflanzenfainilien, which has also been followed as regards 

 nomenclature of families. In other regards the sixth edition 

 of Gray's Manual, and Bailey's revision of Gray's Field, Forest, 

 and Garden Botany have been followed as authorities. Valu- 

 able information concerning the precise time of flowering of 

 many species has been derived from Darlington's Flora Cestrica 

 and Ward's Guide to the Flora of Washington and Vicinity. 



By arrangement with Professor S. M. Tracy a considerable 

 portion of the key and a large number of the following 

 descriptions have been copied (a little simplified) from his 

 Flora of the Southeastern States ; these are designated by an 

 asterisk at the end of each description. 



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