34 



appearance like P. clandestinum, but more slender, with shorter leaves, 

 and smaller spikelets, which are early deciduous. 



Pennsylvania to Texas. 

 v' (a) Var. iniuor, differs from the preceding in its rather smaller size 

 (1£ to 2 feet) and smaller panicle, and the spikelets more persistent. 



Southern States. 



46. P. clandestiuum, Linn. — Culms rigid, 2 to 3 feet high, leafy to the 

 top, rarely branched, upper nodes smooth, the lower often hairy; 

 sheaths smoothish, or the lower ones often rough with papillose, bristly 

 hairs, shorter than the internodes, leaves large, lanceolate to oblong- 

 lanceolate, 4 to 8 inches long, 9 to 15 lines wide, with a cordate, clasping 

 base, very taper-pointed, smooth except the rough margins ; panicle at 

 first partially sheathed, becoming loug-peduuculate, somewhat oblong 

 in outline, 4 to 6 inches long, open and becoming spreading, branches 

 verticiilate ; spikelets 1^ lines long, slightly pubescent or smooth, ob- 

 long-ovate to obovate, the lower glume acutish, nearly one-half as long 

 as the spikelet, second and third equal, mauy nerved ; perfect flower ob- 

 long, pointed. 



New England to Virginia, North Carolina, and westward to Illinois. 



47. P. latifolium, Linn. — Culms 1 to 2^ feet high, smooth, mostly 

 simple, the nodes (generally) and the collar of the sheath soft wooly- 

 hairy, sheaths smooth or more or less pubescent; leaves broadly lance- 

 olate from a cordate, clasping base, 3 to 4 inches long, about three- 

 fourths to 1^ inches wide, tapering to a point, roughish above, smooth, 

 or sparsely hairy below, eleven to thirteen nerved ; panicle more or less 

 exserted, becoming long-peduncled, 2 to 4 inches long, the branches 

 mostly alternate, spreading, rather few flowered; spikelets 1J to 2 lines 

 long, obovate, sparsely pubescent, the lower glume one third, or less 

 than one-half as long as the spikelet, upper one about nine nerved. 



Maine to Texas. 



(a) Variety molle; downy all over. 

 Virginia to Louisiana. 



(b) Var. australis; leaves more contracted at base, and spikelets lar- 

 ger, 2 to 2 J lines. 



Alabama to Texas. 



48. P. scabriusculum, ML f Chap. (P. Nealleyi, Yasey).— Culms 3 to 

 4 feet high, firm, smooth, rarely branched; leaves linear-lanceolate, 4 

 to 8 inches long, one half inch wide, long-pointed, firm, mostly smooth 

 except near the base, sheaths shorter than the joints, mostly smooth, 

 or sometimes sparsely pubescent; panicle larger, 5 to 8 inches long, 

 diffuse, smooth, branches mostly alternate, much divided, the larger 

 ones 3 inches long; spikelets ovate, acutish, sparingly pubescent when 

 young, becoming smooth, lower glume small, second glume strongly 

 seven to nine nerved. 



North Carolina to Texas. 



This is the P. scabriusculum described by Chapman, but does not ap- 



