508 
++ 44+ Spikelets small (about 2 mm. long). 
== Spikelets all long-pedicelled and solitary. 
43. P. capillare L. (OLp wircH Grass.) Annual: culms 5 to 8dm. high, usually 
weak and decumbent: sheaths and often the blades villose or hirsute: panicle 1 to 
3dm. long; branches spreading and diffusely subdivided, hispid, bearing scattered 
long-pedicelled spikelets: spikelets 2 mim. long; the first glume one-third as long as 
the second and third.—In cultivated land everywhere. 
42. P. autumnale Bose. Culms3to5dm, high, erect or decumbent and branching 
near the base: leaves 1 dm. long or less, narrowly lanceolate: panicle 1 to 3dm. long, 
broad and open, the long capillary branches and divergent branchlets bearing single 
spikelets at the extremities: spikelets 2 to 3 mm. long, spindle shaped; first glume 
minute; second and third ciliate near the apex.—Sandy plains throughout Texas. 
Var. PUBIFLORUM Vasey, of southwest Texas, has the empty glumes densely pubes- 
cent all over, and culm and leaves more rigid. 
= — Spikelets short-pedicelled, appressed in rather close clusters along the branches, 
45. P. Hallii Vasey. Culms tufted, 3 to5 dm. high, slender, branching near the 
base: leaves lance-linear, 1 to 1.5 dm. long; sheaths usually papillose: panicle 1.5 
to 2 dm. long, open; branches ascending or divergent, bearing few, short-pedicelled 
spikelets at the ends and on the divergent subdivisions: spikelets 2 to 3dm. long, 
spindle-shaped, acute; first glume one-half as long as the spikelet.—Prairies, central 
Texas and westward to’ Arizona and Mexico. 
46. P. proliferum Lam. (SPROUTING CRAL-GRASS.) Culms rather robust, 5 to 10 
dm. high: leaves 1 to 4 dm. long, smooth or hispidulous toward the apex: panicle 1 
to 3 dm. long, often with small lateral panicles; primary branches spreading, 
bearing appressed spikelets near the ends and on the subdivisions: spikelets 2 to 
3 min. long, spindle-shaped; first glume one-fourth as long as the spikelet.—Moist 
soil, central Texas and eastward. Var. GENICULATUM Vasey las coarse and succu- 
lenteulms 1to2m. high and geniculate, large leaves with inflated often hairy sheaths, 
and a diffusely spreading panicle 3 to 6 dm. long.—Cultivated. 
+ + Tall grasses, 1 m. high or more: panicle large, of virgate or spreading branches. 
2 
spikelets large, § mm. long or more. 
++ Spikelets turgid. 
= Perfect floret nearly equaling the acute empty glumes. 
47. P. bulbosum HBK. (BULBOUS PANIC-GRAss.) Culms 1 to 1.5 m. high 
from a strong bulbiferous rootstock, erect, smooth: leaves narrow, 2 to 4 dm. long: 
panicle oblong, 2 to 4 dm. long; branches mostly alternate, subdivided to the base, 
1 to 2 dm. long: spikelets mostly short-pedicelled on the subdivisions, 3 to 4 mm, 
long, smooth, oblong or spindle-shaped; first glume one-half as long as the spikelet; 
both florets often sterile.—Moist land, central Texas and westward to Arizona. Var. 
MINOR Vasey, of the same region, is smaller throughout except the spikelet. 
= = Perfect floret shorter than the acuminate empty glumes. 
48. P. virgatum L. (Swircu-Grass.) Culms 1 to 1.5 dm. high, erect, simple, 
from strong, creeping rootstocks: leaves flat, 3 to 6 dm. long, smooth except the 
hispid margins: panicle 3 to 5 dm. long; branches numerous, alternate or subverti- 
cillate, diffusely spreading at maturily, rather rigid, bearing numerous spikelets on 
the subdivisions: spikelets ovate, acuminate, 4 to 5mm. long; first glume two-thirds 
as long as the third; this somewhat exceeded by the second.—Variable, often with 
small or undeveloped spikelets, sometimes cultivated. Var. ELONGATUM Vasey has 
a large panicle like the species, but the spikelets empty and narrowly linear.—Texas 
and eastward. 
