GRASS FAMILY. 113 
Basal leaves and those of the culm the same, generally elongated; spikelets acute or acumi- 
nate. 
Spikelets 2’’ long or more. 
Sheaths glabrous. 
Panicle usually 1° long or more; branches spreading; leaves 1° long or more, flat. 
28. P. virgatum. 
Panicle 1° long or less; branches erect or appressed; leaves 6’-1° long, involute on 
the margins, at least at the apex, thick, glaucous. 29. P. amarum., 
Sheaths papillose-pubescent. 30. P. miliaceum. 
Spikelets 1'*"’ long or less. 
Culms stout, finally decumbent and much branched, with lateral panicles from all the 
upper sheaths. 
Sheaths glabrous. 3i. P. proliferum. 
Sheaths pubescent. 32. P. capillare. 
Culms slender, erect or decumbent, branched only at base. 
Spikelets 1'/-1's"’ long, generally single on the ultimate divisions of the panicle. 
Panicle narrow; branches erect, the lower ones about 3’ long; axils naked. 
33. P. flexile. 
Panicle at length diffuse; branches 4/-8' long; axils bearded. 
34. P. autumnale. 
Spikelets less than 1’ long, in pairs. 
Spikelets smooth, elliptic, acute. 35. P. minus. 
Spikelets warty, obovoid, acutish. 36. P. verrucosum. 
Panicle linear; branches appressed; second scale of spikelet obtuse, gibbous at base. 
37. P. gthbum. 
1. Panicum Crus-galli I. Barnyard Grass. Cockspur Grass. (Fig. 243.) 
Panicum Crus-galli I, Sp. Pl. 56. 1753. VA i 
Culms 2°-4° tall, often branching at base. ‘Z Vi 
Sheaths smooth and glabrous; leaves 6/—2° long, Ya 
\{/-1! wide, glabrous, smooth or scabrous; panicle 
composed of 5-15 sessile erect or ascending 
branches, or the lower branches spreading or re- 
flexed; spikelets ovate, green or purple, densely 
crowded in 2-4 rows on one side of the rachis; 
second and third scales about 114’’ long, scabrous 
or hispid, the third scale more or less awned, 
empty, the fourth ovate, abruptly pointed. 
In cultivated and waste places, throughout North 
America except the extreme north. Widely distrib- 
uted as a weed in all cultivated regions. Naturalized 
from Europe. Aug.—Oct, 
Panicum colonum [,., a southern species, related to 
this, but with awnless scales, has been found in south- 
eastern Virginia, too late for illustration here. (See 
Appendix. ) : 
2. Panicum Walteri Pursh. Salt-marsh 
Cockspur Grass. (Fig. 244.) 
Panicum hirtellum Walt. Fl. Car.72. 1788. Not All. 
ein Wallteri Pursh, Fl. Am. Sept. 1:66. 1814. 
Panicum hispidum Muhl. Gram. 107. 1817. 
Panicum Crus-galli var. hispidum Torr. Fl. N. Y. 2: 
424. 1843. 
Culms 3°-6° tall, robust, smooth. Sheaths, at 
least the lower ones, papillose-hispid ; leaves 1° or 
more long, %4/—1/ wide, generally smooth beneath, 
strongly scabrous above ; panicle 6/—18/ long, con- 
sisting of 1o-4o ascending or spreading branches; 
spikelets ovate-lanceolate, densely crowded in 2-4 
rows on one side of the scabrous and hispid rachis, 
brownish purple; second and third scales about 
144’ long, scabrous and hispid, tipped with up- 
wardly barbed awns, sometimes 10-20 times their 
length; fourth scale ovate-lanceolate, acuminate. 
In marshes and ditches, principally within the influ- 
ence of salt water, Ontario to Rhode Island, Florida 
and Louisiana. Aug.—Oct. 
8 
