10 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
been done and only when the number identifies the sheet. Speci- 
mens are listed under the names of the States as they are at present 
recognized and limited. Those labeled as from Indian Territory 
are listed under Oklahoma. 
The maps illustrating distribution are intended to present graph- 
ically the general range of each species within the United States. 
Usually a single dot is placed upon the map in each State in which 
the species is known to grow, as indicated by herbarium specimens. 
In the larger States a dot may be placed in each of the general divi- 
sions in which the species occurs. If the species is found throughout 
a State the dot representing this may be placed in the center, but if 
the species is confined to a particular portion of a State, such as the 
coastal plain of South Carolina, or subtropical Florida, the dot is 
placed in that portion. 
TEXT FIGURES OF SPIKELETS. 
Each species is illustrated by a text figure showing usually two 
views of the spikelet and one view of the fruit. The spikelet is 
usually shown as seen from the front and from the back, but in a few 
species the side view is shown, when this is more characteristic. The 
fruit is placed by the side of the spikelet, and on a line with its posi- 
tion within the spikelet, so that its relation to the other parts is 
readily apparent. These figures are all magnified ten diameters. 
The spikelets from which the drawings are made were usually 
from the type specimens of the species. In most cases where the 
type specimen was not accessible the drawings were made from the 
type or duplicate type specimens of one of the synonyms. In a 
very few cases the drawings were made from specimens which were 
not types or duplicate types. The identity of the specimen from 
which the drawing was made is indicated in each case. 
TERMINOLOGY. 
No new terms are used in the present paper, but it may be well to 
call attention to the term ‘‘lemma,”’ and to certain other terms used in a 
somewhat restricted or modified sense. The lemmas, or the flowering 
glumes of some authors, are the bracts of the spikelet above the empty 
glumes. A lemma is said to be fertile when it bears a perfect flower 
in its axil, and sterile when its flower is staminate or suppressed. 
The term “‘fruit’”’ is used to include the caryopsis and its inclosmg lemma 
and palea. In the subgenus Dichanthelium the terms ‘“ vernal form”’ 
and “autumnal form ”’ are used for the two successive seasonal condi- 
tions of the individuals. The vernal form appears early in the sea- 
son, in spring or early summer, and is followed sooner or later by the 
branched stage called the “autumnal form.” 
