Flora of North America species comparison

30-120 cm;

nodes glabrous.

10-600 cm, erect or decumbent.

glabrous;

ligules shorter than 1 mm, of hairs;

blades to 25 cm long, 2-8 mm wide, flat, scabrous above.

3-8 (10) cm, of uniform width throughout their length, densely spikelike;

rachises scabro-hispid;

bristles 4-12, 2-12 mm, antrorsely barbed, yellow to purple.

terminal, panicles, usually dense and spikelike, occasionally loose and open;

disarticulation usually below the glumes, spikelets falling intact, bristles persistent.

2-2.8 mm, elliptical and turgid.

1-5 mm, usually lanceoloid-ellipsoid, rarely globose, turgid, subsessile to short pedicellate, in fascicles on short branches or single on a short branch, some or all subtended by 1-several, terete bristles (sterile branchlets).

small, ellipsoid to subglobose, compressed dorsiventrally.

glumes about 1/3 as long as the spikelets, 3-veined;

upper glumes 1/2 - 2/3 as long as the spikelets, 5-veined;

lower florets often staminate;

lower lemmas occasionally indurate and faintly transversely rugose;

lower paleas equaling the lower lemmas;

upper lemmas distinctly transversely rugose, often purple-tipped.

glumes membranous, not saccate, less than 1/2 as long as the spikelets, 1-7-veined;

upper glumes membranous to herbaceous at maturity, 1/2 as long as to nearly equaling the upper lemmas in length, 3-9-veined;

lower florets staminate or sterile;

lower lemmas membranous, equaling or rarely exceeding the upper lemmas, rarely absent, not constricted or indurate basally, 5-7-veined;

lower paleas usually hyaline to membranous at maturity, rarely absent or reduced, veins not keeled;

upper florets bisexual;

upper lemmas and paleas indurate, transversely rugose, rarely smooth;

anthers 3, not penicillate;

styles 2, free or fused basally, white or red.

membranous and ciliate or of hairs;

blades flat, folded, or involute, or plicate and petiolate (subg. Ptychophyllum).

= 9.

= 36, 72.