GRASS FAMILY. 



Basal leaves and those of the culm the same, generally elongated; spike lets acute or 



ti cite. 



Spikelets 2" long or more. 

 Sheaths glabrous. 



Panicle usually i long or more; branches spreading; leaves i lot* < 



Panicle i long or less; branches erect or apprewed; leave* 6'-!^ 



the margins, at least at the apex, thick, glau 

 Sheaths papillose-pubescent. 

 Spikelets i' 2 " long or 1, 



Culms stout, finally decumbent and much branched, with lateral Daniel fr,,m mil tk* 



upper sheaths. 

 Sheaths glabrous. . *,///. 



Sheaths pubescent. 

 Culms slender, erect or decumbent, branched only at lia-- 



Spikelets i"-i l A" long, generally single on tlie ultim M * of the pa> 



Panicle narrow; branches erect, the lower one-, at* ml \ !., 



Panicle at length diffuse; branches 4' -8' long; axils bearded. 



Spikelets less than i" long, in pairs. 



Spikelets smooth, elliptic, acute. / 



Spikelets warty, obovoid, acutish. 

 Panicle linear; branches appressed; second scale of spikelet obtuse, gibbous at' base 



lam 



i. Panicum Crus-galli L. Barnyard Grass. Cockspur Grass. (1 



Panicum Crus-galli ^L,. Sp. PI. 56. 1753. 



Culms 2-4 tall, often branching at base. 

 Sheaths smooth and glabrous ; leaves 6'-2 long, 

 #'-i' 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 \y 2 " 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 I,., 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 1'ursh. Salt-marsh 

 Cockspur Gr 



Panicum hirtellutn Walt. 1 t All. 



Pan i nun U'altrri I'ursh. 1 'v 1814. 



Panicum liisftniuin Muhl. Gl 

 Panicum CrtU-ftUU var. hisf>idntH i 



424. i si;,. 



Culms 3-6 tall, robust, smooth. Sheath*, at 

 least the lower ones, papillose-hispid ; leave* i or 

 more long, #'-i' wide, generally smooth beneath. 

 strongly scabrous above ; panicle o'-iy long, con- 

 sisting of 10-40 ascending or spreading branches; 

 spikelets ovate-lanceolate, densely crowded in 1-4 

 rows on one side of the scabrous and hispid rachu. 

 brownish purple; second and third scales about 

 i#" long, scabrous and hispid, lipped with up- 

 wardly barbed awns, sometime* lo-ao time* their 

 length; fourth scale ovate-lanceolate, acuminate. 



In marshes and ditches, priiu-ipaltv within tor influ- 

 ence of salt water, Ontario to Rhode I 

 and Louisiana. Aug. -Oct. 



8 



