24<3 No/th A.uict icdiL Cypoattcc. 
and some i are southern Cyperacere were received through his 
hberaUty. After his decease, I obtained from his amiable widow 
•a portion of the herbarium of the late Dr. Baldwin, which is 
particularly rich in the Cyperaceoe of the southern states. My 
friend Dr. Barratt, of Connecticut, has sent me several exten- 
sive collections of Carices and other plants of this order, from 
the Highlands of New York, Vermont, the White Hills of New 
Hampshire, and Connecticut. Most valuable aid has been 
afforded rae, not only in the communication of specimens, but 
in every part of this work by my friend Dr. Gray. The revi- 
sion of the Rhynchospores is entirely his own ; and the Synopsis 
of North American Carices, I wish to have considered as our 
joint performance. It was thought unnecessary to prepare de- 
scriptions of these plants, except of the new species, as they 
have so recently been made the subjects of monography by Prof. 
Dewey, and also by Dr. Schweinitz and myself. To Charles 
Pickering, M. D., curator of the Herbarium of the Academy of 
JXatural Sciences in Philadelphia, my best thanks are due for 
-the valuable aid he has afforded me in examining the extensive 
collection under his charge. This herbarium contains all 
Mr. Schweinitz's plants, a full set of Dr. Baldwin's, most of 
JVuttall's, besides a vast number of specimens from all parts of 
$he world. The herbarium of Dr. Muhlenberg has been repcat- 
oedly examined, and nearly all his Cyperacese identified. 
Michaux's herbarium in the Jardin des Plantes of Paris was 
•-carefully examined in the summer of 1S33, and most of his Cy- 
^eracese satisfactorily determined. The herbarium of Pursh, 
-now incorporated in the immense collection of A. B. Lambert, 
Esq. of London, was, with the characteristic liberality of that 
gentleman, placed under my inspection ; but I found it very 
-deficient in Cyperaceae. 
It is, perhaps, hardly necessary to state that the exclamation 
point used in the succeeding pages is employed in accordance 
•with the practice of De Candolle and other recent botanical 
■writers. When affixed to the name of an author or correspon- 
dent it indicates that an original or authentic specimen has been 
examined or received by myself. Localhies from A\4iirh 1 
have seen specimens arc designated by the same sign. 
