Flora of North America species comparison

10-40 cm, highly branched above the base in age;

internodes glabrous or pubescent, sometimes nearly lanose.

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

internodes hollow.

cauline;

sheaths shorter than the internodes, glabrous or puberulent;

collars glabrous or pubescent at the sides;

ligules 0.5-1 mm;

blades usually less than 6 cm long, 0.5-1 mm wide, pale green, involute, glabrous or puberulent abaxially.

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 or racemose, 5-10 cm long, 1-2 cm wide, with few spikelets;

rachis nodes glabrous or with straight hairs;

primary branches 1-2 cm, appressed, without axillary pulvini.

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.

overlapping, appressed.

unequal, 1-2-veined;

lower glumes 4-10 mm;

upper glumes 7-15 mm;

calluses about 1 mm;

lemmas 5-7 mm, purple or mottled, junction of the lemma and awns evident;

awns twisted together basally into a 4-26 mm column, free portions 12-50 mm, those of the central and lateral awns similar in length, curved to arcuate basally, straight and divergent distally, disarticulating at the base of the column at maturity;

anthers 3, about 2 mm long.

(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.

4.4-5 mm, chestnut brown.

= 22.

= unknown.