Flora of North America species comparison

2-70 cm, erect or ascending.

45-120(180) cm tall, usually less than 3 mm thick, erect.

mostly glabrous or retrorsely soft pilose, throats usually hairy;

auricles sometimes present on the lower leaves;

ligules 1-3.5(4) mm, glabrous or sparsely hairy, acute to obtuse, lacerate or erose;

blades 8-30 cm long, 1-12 mm wide, flat or becoming involute, glabrous or sparsely pilose to pubescent on 1 or both surfaces.

1-13 cm long, 1-4 cm wide, erect, usually ovoid, open, becoming dense, occasionally reduced to 1 or 2 spikelets;

branches shorter than the spikelets, ascending to erect, straight or almost so.

5-40 cm, lax, open or erect;

lower branches usually shorter than 10 cm, 1-4 per node, ascending to strongly divergent or reflexed, with 1-4 spikelets variously distributed.

(11)14-20(23) mm, lanceolate, terete to moderately laterally compressed;

florets 5-10, bases concealed at maturity;

rachilla internodes concealed at maturity.

20-40 mm, shorter than at least some pedicels and branches, elliptic to lanceolate, strongly laterally compressed, not crowded or overlapping, sometimes purplish, with 4-11 florets.

pilose or glabrous;

lower glumes 5-7 mm, 3-5-veined;

upper glumes 6.5-8 mm, 5-7-veined;

lemmas 6.5-11 mm long, 3-5 mm wide, lanceolate, chartaceous, antrorsely pilose to pubescent, or glabrous proximally or throughout, 7-9-veined, lateral veins prominently ribbed, rounded over the midvein, hyaline margins abruptly or bluntly angled, not inrolled at maturity, apices acute, bifid, teeth shorter than 1 mm;

awns 6-8 mm, usually arising less than 1.5 mm below the lemma apices, straight to recurved at maturity;

anthers 0.6-1.5 mm.

glabrous or pubescent;

lower glumes 7-11 mm, 3-7(9)-veined;

upper glumes 9-13 mm, shorter than the lowest lemma, 5-9(11)-veined;

lemmas 10-16(17) mm, lanceolate, laterally compressed, strongly keeled distally, usually more or less uniformly pubescent or pubescent on the margins only, sometimes glabrous or scabrous, 7-9-veined, veins usually not raised or riblike, apices entire or with acute teeth shorter than 1 mm;

awns 4-17 mm, sometimes slightly geniculate;

anthers 1-6 mm.

equaling or shorter than the paleas, thin, weakly inrolled to flat.

sheaths densely, often retrorsely, pilose;

upper sheaths pubescent or glabrous;

ligules 1-1.5 mm, hairy, obtuse, erose;

blades 2-19 cm long, 1-4 mm wide, abaxial surfaces glabrous or hairy, adaxial surfaces hairy.

= 28.

= 28, 42, 56.