Flora of North America species comparison

60-100 cm, sometimes reclining or decumbent, glabrous.

7-210 cm, branched above the bases, often purplish near the nodes.

not aromatic, sheaths open;

auricles usually absent;

ligules membranous;

blades flat, folded, or involute, those of the uppermost leaves often greatly reduced.

axillary and terminal, of 1, rarely 2, rames, peduncles subtended by a modified leaf;

rames not reflexed, with spikelets in heterogamous sessile-pedicellate spikelet pairs, internodes more or less flattened, filiform to clavate, without a median groove, apices cupulate or fimbriate;

disarticulation in the rame axes, below the sessile spikelets.

somewhat dorsiventrally compressed.

3-5 mm, glabrous.

free of the rame axes, usually pubescent.

not elongate, about as wide as the blade;

ligules to 0.5 mm, ciliolate;

blades 5-15 cm long, 0.5-2 mm wide, involute or flat, glabrous or sparsely hairy basally, with a wide central zone of bulliform cells evident on the adaxial surfaces as a longitudinal stripe of white, spongy tissue.

2-6 cm, eventually long-exserted;

internodes 2-4 mm, straight, glabrous.

spikelets 3.5-4.5 mm;

calluses 0.5-1 mm, hairs to 1.2 mm;

lower glumes glabrous;

upper lemmas acute, entire;

awns 6-10 mm.

spikelets with 2 florets;

glumes exceeding the florets, lanceolate to linear, membranous;

lower glumes enclosing the upper glumes, convex, weakly 2-keeled, with several (sometimes inconspicuous) intercostal veins;

lower florets reduced to hyaline lemmas;

upper florets bisexual, lemmas hyaline, bilobed or bifid to 7/8 of their length (rarely entire), awned from the sinuses;

anthers 3.

spikelets usually as long as or slightly longer than the sessile spikelets, sterile, unawned.

spikelets usually shorter than to as long as the sessile spikelets, occasionally longer, sterile or staminate, with 1 floret, often disarticulating as the rame matures;

lemmas present in staminate spikelets, hyaline, unawned or with a straight awn of less than 10 mm.

= 10.

= 60.