Bulletin - United States National Museum - Smithsonian Institution

FLORA OF WASHINGTON AND VICINITY. 135
Panicum fiUforme, L. Pai^c-Grass.
September.
f Panicum sanguinale, Li. Crab-Grass. Crop-Grass. Finger-Grass.
July.
Panicum anceps, Miclix.
Dry ground; panicle loose; light colored; spikelets 3|'"'" long; fertile flower
2mm long ; bristles at the apex of the flowering glume 5 or 6, crowded. Last of Sep-
tember or first of October.
Panicum agrostoides, Spreng.
Moist ground ; sheaths smooth ; spikelets 2^ long. A few conical bristles
project from the blunt apex of the flowering glume of the fertile flower, at some dis-
tance from the incurved margin. These are often reduced to 2 or 3, well separated
from each other. Panicle very dense, purple. Culms flat ; fertile flowers 1 long,
lanceolate or linear. Last of September or first of October.
Panicum proliferum, Lam.
Not common. Late in September.
t Panicum capillare, L. Old-witch Grass.
August.
Panicum virgatum, L
July, August.
t Panicum latifolium, L.
End of May.
Panicum latifolium, L., var. molle, Vasey, n. v.
This variety is soft-velvety throughout and especially on the sheaths and under
surface of the leaves; even the culms below the joints are downy, and the joints
themselves are bearded with long and very soft white hairs. The flowers are triandrous
and purplish. End of May.
Panicum clandestinum, L.
Forms with small heads occur uniting this with wide-leaved states of P. diclwtomum.
June.
Panicum microcarpon, Muhl.
The late flowering-time of this species is a convenient means of distinguishing it
from any of the broad-leaved forms of P. dichotomum. July.
Panicum viscidum, Ell.
Reform School. Last half of July.
Panicum pauciflorum, Ell.
High Island. May 25, 1879.
Panicum dichotomum, L.
I distinguished twelve well-marked forms, probably embracing several good
species.
Dr. Vasey has kindly given this species a special study expressly for this work,
and chiefly from specimens furnished him from this locality by myself or of his own
collection, and he makes the following report upon it
"It is very diflicult to classify the varieties of this polymorphous species. So far
as our forms are concerned, they may be grouped as follows
:
: