vi PREFACE. 
tries, authorities are cited and synonymy is given as far as they 
relate to the American habitat, with only partial and general refer- 
ences to foreign botany. 
It is intended to give with the final volume a full bibliography, 
not only of the works and articles here cited, but of all others relat- 
ing to the North American flora. The abbreviations of titles that 
are here used, though necessarily concise, will usually suffice for the 
ready identification of the works cited, without the aid which such 
bibliography would give. In some instances, however, authors of 
single works of frequent recurrence are referred to by name only, as 
Walter (Flora Caroliniana), Persoon (Synopsis Plantarum), Elliott 
(Sketch of the Botany of South Carolina), Chapman (Flora of the 
Southern States), etc. In case of several editions of the same work, 
the first edition is the one cited unless it is otherwise specified, 
excepting the common manuals of the Eastern flora, of which the 
later editions have been used (Eaton & Wright, North American 
Botany, 1841, which is the eighth edition of Amos Eaton’s Manual 
of Botany; Wood, Class-Book, 1861; Gray, Manual, 5 ed. 1869). 
The Genera Plantarum of Bentham & Hooker has been followed in 
the sequence of the orders, while the genera and species are arranged 
alphabetically for greater facility of reference. The authorities 
under each specific name, as also the citations from each author, 
are arranged in chronological order. Citations of plates or figures 
are made more prominent by the use of heavy-faced type; where 
the reference is simply to a catalogue name or habitat, without 
any note descriptive or otherwise important, the numerals are in 
antique type. Introduced species have the specific name in small 
capitals. 
SERENO WATSON. 
CAMBRIDGE, March 1, 1878. 
