Flora of North America species comparison

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

internodes hollow.

(30)45-80 cm, branching at the lower nodes, often diffusely so;

nodes and internodes glabrous.

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.

cauline;

sheaths shorter or slightly longer than the internodes, glabrous or with straight hairs, sometimes pilose-floccose;

collars glabrous or pilose at the sides;

ligules about 0.5 mm;

blades (6)10-20 cm long, 1-2(3) mm wide, yellow-green, turning reddish late in the season, involute to loosely folded, abaxial surfaces smooth or scabrous near the base, sometimes pubescent distally, adaxial surfaces usually glabrous, sometimes scabrous or pubescent, lateral veins about twice as thick as the inner veins.

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.

paniculate, 10-20 cm long, 2-7 cm wide;

rachis nodes glabrous;

primary branches stiffly ascending, with axillary pulvini, with 3-9 spikelets.

overlapping, appressed.

in fan-shaped clusters, pedicels with axillary pulvini.

(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.

10-17 mm, about equal, light to dark brown, glabrous or rarely sparsely pilose, 1-veined, apices cleft and awned, awns 2-5 mm;

calluses 1-2.5 mm;

lemmas 7-10 mm, gray to light brown, narrowing to a 2-5(7) mm beak, junction of the lemma and awns evident;

awns 20-28 mm, similar in length, curved to strongly arcuate near the base, not forming a column, straight and divergent distally, disarticulating at maturity;

anthers 3, 1-2 mm, dark purple.

4.4-5 mm, chestnut brown.

7-8 mm, smooth, chestnut brown.

= unknown.

= unknown.