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.

30-130 cm, terete to slightly compressed.

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.

laterally compressed, glabrous or sparsely to densely pilose or villous, especially at the summit;

ligules less than 0.5 mm, membranous, erose, often brownish;

blades 10-50 cm long, 4-12 mm wide, erect, adaxial surfaces pilose at least basally, glabrous or pilose abaxially.

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, 1/4 - 2/3 as wide as long, well-exserted at anthesis;

branches relatively few, stiffly spreading or ascending; ultimate branchlets 1-sided;

pedicels 0.1-3 mm, scabridulous to scabrous, appressed.

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

2.3-3.9 mm, narrowly ellipsoid to ovoid, usually subsessile, usually pale to yellowish-green, glabrous, often falcate and gaping at the apices, rarely lanceolate, densely crowded on short, appressed branchlets, set obliquely on short pedicels.

A-A as long as the spikelets, 3-veined, keels scabrous, apices acute;

upper glumes and lower lemmas subequal, keeled, beaked, usually gaping at the apices;

lower florets sterile;

lower paleas subequal to the lower lemmas;

upper florets 1.5-2.2 mm long, about 1 mm wide, 2/5 – 3/4 as long as the spikelets, apices with a tuft of minute, thick hairs;

upper lemmas thick, stiff, clasping the upper paleas throughout their length.

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.

= 18, 36.