244 Nurlh American Ci/peracccp. 
has a similar range. Eriophorum is a northern genus, 
only one of its species extending heyond Pennsylvania. 
Ch.-etocyperus is peculiar to the south. Fimbristylis does not 
reach the northern limits of the United States. Isolepis is 
chiefly southern. Our solitary species of Trichelostylis occurs 
in nearly all parts of North America south of Canada. 
Rhynchosporeae are, with few exceptions, southern plants. 
Dichromena is not found north of Vu-ginia nor far from the 
ocean. Two Psilocaryoe are soudiern, and a third has been 
observed only in Massachusetts. Of the 28 species of Rhyn- 
chospora but four are found as far north as Boston, and only 
eight belong to the middle states ; the remainder are mostly 
peculiar to the southern states, but many of them extend west 
to Texas. Of the two species of Ceratoschoenus, one inhabits 
a large part of the United States south of Delaware and west 
to the Mississippi ; the other is found only in New England. 
The tribe Cladiese is represented by two species of the 
genus Cladium, one of wliich is northern, the other southern. 
Of Sclerieos we have but two genera and eleven species, two 
or three of which have an extensive range in latitude and longi- 
tude, but most of them are southern and are confined to the 
vicinity of the ocean. 
A solitary species "of the small tribe Elyneae inhabits the 
boreal regions of the continent. 
The vast genus Carex, which almost exclusively consthutes 
the tribe Cariceas, predominates in the northern parts of the 
continent, and many of its species are peculiar to the boreal 
and arctic regions ; but a large number inhabit almost every part 
of North America. Of Uncinia we have but a single species, a 
native of British America. 
It remains for me to state the sources from whence I obtain- 
ed a large portion of the materials used in the preparation of 
this monograph. 
To my much valued friend Sir William J. Hooker I am 
greatly indebted, not only for free access to his unrivalled her- 
barium, but for a liberal supply of specimens from the collec- 
tions made bv Dr. Richardson, T. Drummond and other travel- 
