

GRASS FAMILY. 

 36. Panicum verrucdsum Muhl. Warty Vanicum. (Fig. ,78.) 



j 



inititm rerrucosum Muhl. Gram. 113. 1817. 



tnicum debile Ell. Bot. S. C. & Ga. i: 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 z'-j' 

 long, i "-4" wide, erect or ascending, glabrous, rough 

 on the margins; panicle 3'-i2 r long, its lower 

 branches 2 / -6 / long, naked below, strict and ascend- 



ig, or lax and spreading; spikelets about %" long, 



liptic, acutish, borne in pairs along the branches, 



,e first scale about one-quarter as long as the warty 

 :ond and third, the fourth scale apiculate. 



Moist soil, Massachusetts to Florida, west to Louisiana 

 ~ itly near the coast. July-Sept. 



37. Panicum gibbum Ell. Gibbous Panicum. . Fi K . 279. > 



Panicum gibbum Ell. Not. S. C. it r.a i u, 



Culms erect from a creeping base. a-6 e tall. 

 dichotomously branched below. Lower sheaths 

 densely hirsute, the upper generally glabrous ; leave* 

 3 / -7 / long, 2 // -io // wide, usually spreading, more or 

 less pubescent ; panicle $'-<)' long, dense and con- 

 tracted ; branches }4'-i' long, erect; spikelets l#"- 

 2" long, elliptic, somewhat acute; first scale about one- 

 quarter as long as tho spikelet ; second scale gibbOM 

 at base, n-nerved; third scale about equalling the 

 second, 7-nerved, empty, the fourth one shorter than 

 the second. 



Swamps. Virginia to Tennessee, >uth t<> Florida aad 

 Louisiana. Also in Cuba. July - 



13. IXOPHORUS Schlecht. Linnaea, 31: 420. 1861 



[SETARIA Beauv. Agrost. 113. 1812. Not Ach. 179*.] 



Mostly annual grasses with erect culms, flat leaves, the inflorescence in spikc-hke panicle*. 

 Spikelets i-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 palct and rarely a laminate 

 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 spikek-ts of some species.] 



Species about 10, in temperate and tropical regions, 

 duced from the Old World. 



Those occurring in our ransr ' 



Bristles downwardly barbed. 

 Bristles upwardly barbed. 



Mature fourth scale of spikelet oval in outline, very convex, almost In-mi-phrru 



transversely rugose. 

 Mature fourth scale generally elliptic in outline, only nicKK-r.it finely Iran* 



rugose or pitted, striate. 

 vSpikes i'-3&' long, %' or less thick; spikelets about i" long, always mu> 



the green bristles. 



Spikes 4' -9' long, %'-2' thick; spikelets about i*;" long, equalled or exceeded 

 usually purplish bristles. 



