GRASS FAMILY. 125 
36. Panicum verrucdsum Muhl. Warty Panicum. (Fig. 278.) 
Panicum verrucosum Muhl, Gram. 113. 1817. 
Panicum debile Ell. Bot. S.C. & Ga. 1: 129. 1817. Not 
Desf. 1800. 
Culms erect or decumbent, slender, generally much 
branched at base. Sheaths glabrous, much shorter 
than the internodes ; ligule short, ciliate ; leaves 2’—7’ 
long, 1’’-4’’ wide, erect or ascending, glabrous, rough 
on the margins; panicle 3/-12’ long, its lower 
branches 2’—6’ long, naked below, strict and ascend- 
ing, or lax and spreading; spikelets about 4’ long, 
elliptic, acutish, borne in pairs along the branches, 
the first scale about one-quarter as long as the warty 
second and third, the fourth scale apiculate. 
Moist soil, Massachusetts to Florida, west to Louisiana, 
mostly near the coast. July—Sept. 
Panicum gibbum Ell. Bot. S. C. & Ga. 1: 116. 1817. 
Culms erect from a creeping base, 2°-6° tall, 
dichotomously branched below. Lower sheaths 
densely hirsute, the upper generally glabrous ; leaves 
3/-7’ long, 2’’-10’’ wide, usually spreading, more or 
less pubescent; panicle 3/-9’ long, dense and con- 
tracted; branches 14’-1’ long, erect; spikelets 114//— 
2/’ long, elliptic, somewhat acute; first scale about one- 
quarter as long as the spikelet ; second scale gibbous 
at base, 11-nerved; third scale about equalling the 
second, 7-nerved, empty, the fourth one shorter than 
the second. 
Swamps, Virginia to Tennessee, south to Florida and 
Louisiana. Alsoin Cuba. July—Sept. 
13. IXOPHORUS Schlecht. Linnaea, 31: 420. 1861-2. 
[SETARIA Beauv. Agrost. 113. 1812. Not Ach. 1798.] 
Mostly annual grasses with erect culms, flat leaves, the inflorescence in spike-like panicles, 
Spikelets 1-flowered, or rarely with a second staminate flower, the basal bristles single or in 
clusters below the articulation of the rachilla, and therefore persistent. Scales of the spike- 
let 4, the three outer membranous, the third often subtending a palet and rarely a staminate 
flower ; the inner or fourth scale chartaceous, subtending a palet of similar texture and a 
perfect flower. Stamens 3. Styles distinct, elongated. Stigmas plumose. Grain free, 
enclosed in the scales. [Greek, in reference to the viscid spikelets of some species. ] 
Species about 10, in temperate and tropical regions. Those occurring in our range are intro- 
duced from the Old World. 
Bristles downwardly barbed. 1. LZ. vertictllalus. 
Bristles upwardly barbed. 
Mature fourth scale of spikelet oval in outline, very convex, almost hemispheric, coarsely 
transversely rugose. 2. fT. glaucus. 
Mature fourth scale generally elliptic in outline, only moderately convex, finely transversely 
rugose or pitted, striate. 
Spikes 1'-3'%' long, %’ or less thick; spikelets about 1’ long, always much exceeded by 
the green bristles. 3. I. viridis. 
Spikes 4'-9' long, %'-2' thick; spikelets about 1%'’ long, equalled or exceeded by the 
usually purplish bristles, 4. L. Ltalicus. 
