26 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
DESCRIPTION. 
Plants pale green, tufted, from short horizontal rootstocks; culms erect or ascending, 
25 to 60 cm. high, commonly branching at the base and lower nodes, scabrous at least 
below the nodes; sheaths nearly as long as the 
internodes or the lower overlapping, not com- 
pressed, sparingly papillose-pilose, especially 
along the margins and at the summit; ligule 
about 1 mm. long, with longer hairs at the sides; 
blades rather firm, erect or ascending, 5 to 12 cm. 
long, the lower shorter and more spreading, 2 to 
4 mm. wide, tapering to an involute tip, not 
narrowed at base, but about as broad as the 
sheath, sparsely papillose-pilose on both sur- 
faces, at least toward the base; sometimes 
sparsely ciliate; panicles very slender, 5 to 20 
cm. long, not conspicuously interrupted, their 
branches erect, the ultimate branchlets of 1 to 4 subsessile spikelets, the setiform 
prolongation of the axis usually not exceeding the short-pediceled spikelet; 
spikelets 2.4 to 2.6 mm, long, 1.4 to 1.5 mm. wide, obovate, subacute, turgid, 
plano-convex; first glume clasping, 
about half the length of the spikelet, 
subacute or acute, 5-nerved; second 
glume and sterile lemma subequal, 
scarcely covering the fruit at matu- 
rity, strongly 7 to 9-nerved; fruit 2.2 
to 2.3 mm, long, 1.4 mm. wide, ellip- 
tic, acute. 
Fig. 5.—P, ramisetum. From type 
specimen. 
DISTRIBUTION, 
Sandy plains and prairies, southern 
Texas and northern Mexico. 
Texas: Big Springs, Tracy 7958, 8229; Kingsville, Tracy 8879; Encinal, Griffiths 
6380; Laredo, Nealley in 1891, Pringle 2377, Sauvignet in 1891; Eagle Pass, 
Havard 98; San Diego, Nealley 62, Smith in 1897; without locality, Buckley 
in 1881, Nealley in 1887, 1888, 1889, and 1892. 
Mexico: State of Coahuila, near Diaz, Pringle 8323. 
Fig. 6.—Distribution of P. ramisetum. 
5. Panicum reverchoni Vasey. 
Panicum reverchoni Vasey, U.S. Dept. Agr. Div. Bot. Bull. 8: 25. 1889. ‘Texas 
(Reverchon).’? The type, in the National Herbarium, was collected by J. Rever- 
chon, near Dallas, Texas, and distributed in ‘‘Curtiss, North American Plants No, I,” 
as Setaria uniseta Fourn., 
DESCRIPTION. 
Plants tufted from short rootstocks, branching at the base; culms stiffly erect, 30 to 
70 cm. high, simple or occasionally bearing one or two sterile branches, slender, sub- 
compressed, glabrous or the lower internodes strigose, the nodes appressed-pubescent; 
sheaths mostly longer than the internodes, ciliate on the margin toward the summit, 
otherwise glabrous, often slightly scabrous, or the lowermost sometimes sparsely 
strigose; ligule about 0.3 mm. long; blades erect, stiff, 5 to 20 cm. long, 2 to3 mm. wide, 
flat or involute toward the apex and base (the blades of the basal shoots commonly 
involute-setaceous), scabrous on both surfaces, especially the upper, at the base nar- 
rower than the sheath, the lower commonly disarticulating at this point; panicles 
