Flora of North America species comparison

30-120 cm, erect, unbranched.

90-150 cm, often thickened basally, stiffly erect, usually unbranched;

internodes hollow.

basal and cauline, pale green, sometimes glaucous;

sheaths longer or shorter than the internodes, glabrous except at the summit;

collars densely to sparsely pilose or glabrous;

ligules less than 0.5 mm;

blades 8-30 cm long, 1-2 mm wide, usually flat, often curled at maturity.

cauline;

sheaths usually shorter than the internodes, glabrous, remaining intact at maturity;

collars glabrous;

ligules to 0.1 mm;

blades (8)10-30(35) cm long, 2-4 mm wide, usually flat, occasionally loosely involute, lax, glabrous, light yellow-green to bluish-green when young, drying brownish.

paniculate, 10-30 cm long, (4)8-26 cm wide;

rachis nodes with straight hairs, hairs to 0.8 mm;

primary branches 6-16 cm, abruptly spreading to divaricate, stiff to lax, with axillary pulvini, usually not spikelet-bearing below midlength.

paniculate, 25-45(55) cm long, 3-6 cm wide;

nodes glabrous;

primary branches 2-8 cm, usually single or paired, appressed to erect, occasionally ascending, without axillary pulvini, with (1)2-12 spikelets.

appressed, rarely spreading.

overlapping, appressed.

1(3)-veined, brown or purple at maturity, acuminate;

lower glumes 6-13 mm;

upper glumes equaling or to 4 mm shorter than the lower glumes;

calluses 0.8-1.2 mm;

lemmas 10-15(17) mm, terminating in a strongly twisted, 2-4 mm awnlike beak, junction with the awns not conspicuous;

awns not disarticulating at maturity;

central awns 5-12 mm, markedly bent near the base;

lateral awns absent or to 1(3) mm, erect;

anthers 1.2-2.2 mm, brownish.

(7.5)9-13.5 mm, subequal, stiff, glabrous or scabridulous, light brown or greenish-brown;

lower glumes prominently 2-veined, 2-keeled by the development of 1 lateral vein, shortly (1-2 mm) awn-tipped;

upper glumes 1-veined, shortly (0.5-1 mm) awn-tipped;

calluses 1-1.4 mm;

lemmas 6-9 mm, glabrous, 0.3-0.5 mm wide distally, light tan to brown, junction with the awns not evident;

awns not disarticulating at maturity;

central awns 15-40 mm, usually strongly curved basally, strongly divergent to horizontal distally;

lateral awns 8-35 mm, at least 1/2 as long as the central awns, erect to strongly divergent;

anthers 3, about 3 mm, purplish.

6-8 mm.

4.4-5 mm, chestnut brown.

= 22, 44.

= unknown.