Flora of North America species comparison

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

internodes hollow.

30-80(100) cm, erect, unbranched.

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.

mostly basal;

sheaths usually longer than the internodes, mostly glabrous, throat sometimes with hairs, not disintegrating into threadlike fibers;

collars glabrous or with hairs at the sides;

ligules 0.2-0.4 mm;

blades 10-25(30) cm long, 1-3 mm wide, usually flat, often curling like wood shavings when mature, glabrous.

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.

spikelike panicles, 10-25 cm long, 1-3 cm wide;

nodes glabrous or with straight, about 0.5 mm hairs;

primary branches 2-6 cm, appressed, without axillary pulvini, with 2-8 spikelets.

overlapping, appressed.

(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.

10-15(18) mm, brownish, acuminate to awned, awns to 3 mm;

lower glumes slightly shorter than to equaling the upper glumes, 1-2-veined;

calluses 1-1.8 mm;

lemmas 12-18 mm, glabrous, rarely sparsely pilose, terminating in a 3-6 mm twisted column, junction with the awns not conspicuous;

awns 20-35 mm, straight to curved basally, ascending distally, not disarticulating at maturity;

central awns 20-35 mm;

lateral awns slightly shorter than the central awns;

anthers 3, 1.3-1.9 mm.

4.4-5 mm, chestnut brown.

= unknown.

= 22.