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.

60-130 cm, thick, glabrous, rooting profusely at the lower nodes;

nodes glabrous, often with a dark green band.

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.

usually shorter than the internodes, glabrous, prominently veined;

ligules 0.5-1.5 mm;

blades 15-40 cm long, 7-25 mm wide, tapering from midlength, flat, both surfaces glabrous, bases subcordate, margins scabrous to smooth, widest at the base, apices acute.

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.

10-40 cm long, 7-20 cm wide, open, with straight, rigid rachises;

branches whorled, stiffly ascending, with short, appressed, higher order branches; ultimate branchlets 1-sided, with solitary spikelets or small clusters of spikelets;

pedicels 0.1-1.5 mm.

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

5.5-7 mm long, about 1 mm wide, narrowly lanceoloid, glabrous.

spreading apart at maturity, keeled, prominently veined, scabrous along the midveins;

lower glumes nearly as long as the lower lemmas;

upper glumes and lower lemmas 3-veined, spreading, greatly exceeding the upper florets, lower lemmas longer than the upper glumes, arcuate;

lower florets sterile;

lower paleas thin;

upper florets 1.9-2.2 mm, less than 1/3 as long as the spikelets, obovoid, lustrous, pale to brownish, acute, often short-stipitate.

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.

= 40.