Flora of North America species comparison

15-130 cm, slender to stout, not woody, erect to decumbent, straight to zigzag, simple to profusely branched;

nodes sparsely to densely pilose.

50-200 cm, strongly compressed, decumbent-erect, glaucous;

nodes glabrous.

rounded, hirsute or hispid, hairs papillose-based;

ligules membranous, ciliate, cilia 0.5-1.5 mm;

blades 5-40 cm long, 3-18 mm wide, linear, spreading.

keeled, glabrous or pubescent near the throat, upper sheaths much shorter than the internodes;

ligules 0.5-2 mm, membranous, dissected ciliate;

blades 20-35 cm long, 7-17 mm wide, flat, glabrous on both surfaces or the adaxial surfaces sparsely pilose.

13-50 cm long, 7-24 cm wide, usually more than 1/2 as long as the plants, included at the base or exserted at maturity, disarticulating at the base of the peduncles at maturity and becoming a tumbleweed;

branches spreading;

pedicels 0.5-2.8 mm, scabrous, pilose.

12-50 cm, about 2/3 as wide, open;

primary branches spreading, often verticillate at the lower nodes;

pedicels 0.2-4 mm, scabrous, spreading.

1.9-4 mm, ellipsoid to lanceoloid, often red-purple, glabrous.

2.5-3.4 mm long, about 1.2 mm wide, ellipsoid, glabrous.

usually shorter than 1.7 mm, up to 1/2 as long as the spikelets, 3-veined, subacute;

upper glumes and lower lemmas subequal, scarcely longer than the upper florets, 5-veined;

lower florets sterile or staminate;

upper florets 2.9-3 mm long, about 1 mm wide, ellipsoid, glabrous, dull, pale, obscurely transversely rugose, apices minutely pubescent.

florets sterile;

lower glumes 1/3– 1/2 as long as the spikelets, 1-3-veined;

upper glumes 1.8-3.1 mm, 7-9-veined, midveins scabridulous;

lower lemmas 1.9-3 mm, extending 0.4-1.1 mm beyond the upper florets, often stiff, straight, prominently veined distally;

upper florets stramineous or nigrescent, sometimes with a prominent lunate scar at the base, often disarticulating before the glumes, leaving the empty glumes and lower lemmas temporarily persisting on the panicles.

= 18.

= unknown.