125. 
species not yet discovered at the Chesapeake Bay Center; the writer 
has collected at the Center 209 species which are not included on 
Stieber's list for the county. This complementary collection rein- 
forces Stieber's observation on the need for further systematic 
floristic study of the region, and supports the writer's provision 
for the inclusion of additional taxa in the keys of the present list. 
To prevent the checklist keys from becoming topheavy with "expected" 
taxa, the writer has used the following criteria in selecting them: 
abe They must be named as established in F. J. Hermann's 
A Checklist of Plants in the Washington-Baltimore Area, 2nd. 
edition (Hermann, 1946). 
Dis They must be described in the available literature as 
having a distribution which includes the Maryland Coastal Plain, 
and must not be restricted to swamps or other habitats which 
do not occur at the Center. 
Be They must not be too numerous to keep the keys relatively 
simple and short. 
This system of including "expected" taxa in the keys has already 
facilitated the identification of several species listed in Appendix I. 
Further research at the Center may reveal other taxa not yet listed as 
"expected.'"' The identification of new taxa may be confirmed by the 
use of Gray's Manual. 
Nomenclature 
The nomenclature of the checklist follows that of Gray's Manual 
of Botany, 8th edition, except in the family Gramineae; there, 
