Flora of North America species comparison

30-120 cm, erect, unbranched.

45-100 cm, unbranched or sparingly branched.

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 shorter than the internodes, glabrous except for occasional hairs at the summit;

collars glabrous, or with a few pilose hairs at the sides;

ligules about 0.5 mm;

blades 12-28 cm long, 1-3 mm wide, usually folded or loosely involute, light yellow-green, glabrous abaxially, puberulent adaxially.

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.

dense panicles, (3)8-24 cm long, 2-4 cm wide, somewhat spirally twisted in age;

nodes glabrous or strigillose, hairs about 0.1 mm;

primary branches 2-4 cm, tightly appressed, without axillary pulvini, with 6-10 spikelets per branch.

appressed, rarely spreading.

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.

lanceolate, 1-veined;

lower glumes 3.5-4.5 mm, abruptly contracted to a 4-12 mm awn;

upper glumes 7-10 mm, gradually narrowed to a 10-12 mm awn;

calluses about 2 mm;

lemmas 5-6 mm, dark brown or purplish, terminating in a straight or twisted beak 7-30 mm long, about 0.2 mm wide, beak often disarticulating, no obvious zone of articulation developed, junction of the beak and awns sometimes evident;

awns usually unequal, strongly curved and twisted at the base, straight distally, sometimes disarticulating at maturity;

central awns (10)20-30 mm;

lateral awns 10-20(25) mm, at least 1/2 as long as and evidently thinner than the central awns;

anthers 3, about 1 mm, brown.

6-8 mm.

4-5 mm, including the delicate style column.

= 22, 44.

= unknown.