58 Rhodora [APRIL 
For this purpose I had recourse to the Gray Herbarium and, by 
the courtesy of Dr. Millspaugh and Dr. Pennell, the herbaria in Chic- 
ago and New York were referred to through correspondence. Mr. 
Charles C. Deam, State Forester of Indiana, kindly assisted me by 
furnishing notes of his collections in Indiana. And, lastly, reference . 
was had to the writings of many authors citied in the text. The pres- 
ent paper is the summary of these investigations. 
DEFINITION OF THE COASTAL PLAIN ELEMENT. 
The coastal plain of the geologists is that flat area lying between the 
coast and the piedmont and extending from the Gulf of Mexico to 
southern New England. It is usually underlaid by Cretaceous de- 
posits but in various areas and especially on its northward extensions 
is overlaid with Tertiary sands. But by the coastal plain florais meant 
the flora of that area of acid bogs, sand barrens, savannahs and marsh- 
es anywhere from the Gulf of Mexico and Florida to Cape Cod, Nova 
Scotia and Newfoundland. It does not include the flora of salt marshes, 
estuaries, the piedmont country which lies just back of the coastal 
plain and parallel to it, nor does it include any of those plants which, 
though abundant on the coastal plain are found in a fairly general 
way upon other areas, such as Cenchrus carolinianus, Quercus ilici- 
folia, Strophostyles helvola, Tephrosia virginiana, Lespedeza capitata, 
etc. I have, however, included in the list of inland extensions of the 
coastal plain some species of the dunes and strands of the Atlantic 
coast. The dunes and strands, it is true, are better considered as 
littoral features than as strictly of the coastal plain and its floristic 
extensions which are characterized rather by savannahs and pond- 
holes and accompanying features than by moving sand and wave- 
beaten shores. The coastal plain is covered by a very distinctive 
and endemic vegetation. But the dunes are characterized by plants 
which occur or have close affinities with species occurring more gener- 
ally around the basin of the North Atlantic, and extend inland with 
a greater frequency than the coastal plain species. These in cases 
where they tend to follow coastal plain ranges, I have included in 
the coastal plain element. It is thus clear that in speaking of the 
“coastal plain,” I shall have in mind that of the botanist rather than 
the geologist. 
InLAND EXTENSIONS OF THE CoaAsTAL PLAIN FLORA. 
Soil and other controlling conditicns of the coastal plain are du- 
plicated in inland stations at various points, and in such places iso- 
