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.

100-300 cm tall, 4-10 mm thick, decumbent, semi-woody at the base, simple or branching from the middle nodes, prophylls prominent, to 15 cm;

nodes contracted, pilose, sericeous;

internodes glabrous or with papillose-based hairs below the nodes.

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.

shorter or longer than the internodes, rounded, sparsely hispid, hairs papillose-based, thick, fragile, penetrating and irritating the skin when handled, margins glabrous or ciliate;

collars more densely pubescent than the sheaths, hairs papillose-based;

ligules 1.5-2 mm, with longer hairs immediately behind, growing from the base of the blades;

blades 20-50 cm long, 15-40 mm wide, spreading, flat or with involute margins, bases subcordate to cordate, margins glabrous or sparsely hairy.

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.

terminal, 25-45 cm long, 5-15 cm wide, lax, contracted to diffuse, not breaking at the base and becoming tumbleweeds, all or most secondary branches confined to the distal 1/3;

lower branches whorled;

pedicels 0.5-2 mm, appressed.

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

1.8-2.5 mm long, 0.5-1 mm wide, narrowly ellipsoid, glabrous.

0.7-1.4 mm, about 1/2 as long as the spikelets, 3-5-veined, acute to attenuate;

upper glumes and lower lemmas subequal, about as long as the spikelets, 7-11-veined;

lower florets sterile;

lower paleas 1.3-1.7 mm;

upper florets 1.2-1.6 mm long, 0.5-0.7 mm wide, glabrous, smooth, shiny, chestnut brown to dark brown.

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.

= 36.