GRAMINE^E. (GRASS FAMILY.) 579 



++ Calm-leaves broadly lanceolate or wider, with 9-15 principal nerves. 



11. P. latifolium, L. (excl. syn. Sloane, &c.) Culm (l-2 high), 

 smooth; the joints and the orifice of the throat or margins of the otherwise 

 smooth sheaths often bearded with soft woolly hairs ; leaves broadly oMong-lanceolato 

 from a heart-clasping base (often 1' wide), taper-pointed, 11 - 15-nerved, smooth, 

 or spanngly downy-hairy; panicle more or less exserted (2' -3' long), usually 

 long-peduncled, the hranches spreading; spikelets obovate, l" long, downy; low- 

 er glume ovate, not half the length of the many-nerved upper one ; sterile flower 

 often (but not always) with 3 stamens. 1J. (P. Walteri, Poir.) Moist thick- 

 ets ; common. June - Aug. 



12. P. clandestllllllll, L. Culm rigid (1- 3 high), very leafy to the 

 top, at length producing appressed branches, the joints naked; sheaths rough with 

 papilla bearing very stiff and spreading bristly hairs ; leaves oblong-lanceolate 

 from a heart-clasping base, very taper-pointed ; lateral panicles and usually also 

 the terminal panicle more or less enclosed in the sheaths, or, in var. PEDUNCULA- 

 TUM (P. pedunculatum, Torr.), with the terminal one at length long-peduncled: 



otherwise resembling No. 1 1 ; but the spikelets more ovoid, often smooth ; the 

 lower flower (always ?) neutral. Low thickets and river-banks ; rather com- 

 mon. July -Sept. 



13. P. microcarpon, Muhl. Culm and sheaths as in No. 11; the 

 broadly lanceolate leaves nearly similar, but longer in proportion and less point- 

 ed, not dilated at the rounded bristly-ciliate base, very rough-margined, the up- 

 per surface roughish ; panicle soon exserted on a slender peduncle, very many- 

 flowered, narrowly oblong (3' -7' long) ; spikelets about " long, ovoid, smooth 

 or smoothish ; lower glume orbicular and very small, ty (P. multiflorum, EU. ? 

 not of Poir. ) Dry or moist thickets, Pennsylvania and Michigan to Illinois, 

 and southward. July -Sept. 



14. P. xaiithopiiysimi, Gray. Culm simple, or at length branched 

 near the base (9' -15' high); sheaths hairy; leaves lanceolate, very acute (4'-6 ; 

 long by ^' wide), not dilated at the ciliate-bearded clasjnng base, smooth except the 

 margins, strongly 3-ll-nerved; panicle long-peduncled, simple, contracted, the ap- 

 pressed branches bearing few roitndish-obovafe spikelets (about l" long) ; lower 

 glume ovate, acutish, one third or half the length of the 9-ncrved upper one. 1J. 



Dry and sandy soil, Maine to Wisconsin, and northward ; rare. June. 

 Plant yellowish-green : spikelets minutely downy : sterile flower sometimes 

 staminate. 



15. P. vise id u m, Ell. Culms upright or ascending, at length much 

 branched, leafy to the top, densely velvety-downy all over, as also the sheaths, with 

 reflexcd soft and often clammy hairs, except a ring below each joint ; kaves likewise 

 velvety all over, lanceolate (^ ivide), 11 -\3-nerced; panicles spreading, the lateral 

 ones included; spikelets obovate, 1" or l" long, downy; the roundish lower 

 glume scarcely one fourth the length of the 7-nerved upper one. Damp soil, 

 S. New Jersey to Virginia, and southward. Aug. 



18. P. paiicifloriim, Ell.? Culms upright, at length much branched 

 and reclining (1 - 2 long), roughish ; kaves lanceolate (3' - 5' long by ' - ' wide), 

 rather faintly 9-ncrra/, hairy or smooth, fringed on the whoh margin or next the 



