Flora of North America species comparison

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

internodes glabrous or pubescent, sometimes nearly lanose.

60-100 cm, erect, unbranched.

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.

mostly basal;

sheaths longer than the internodes, glabrous, basal sheaths many-veined, shredding into threadlike segments at maturity;

collars glabrous or sparsely pilose at the corners;

ligules 0.1-0.2 mm;

blades 10-55 cm long, 1-3 mm wide, flat to folded, glabrous, pale green to yellow-green, central veins separate and narrow, without a well-defined midrib, lateral veins forming a thickened region on each margin.

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, (10)20-45 cm long, 2-6 cm wide;

nodes glabrous;

primary branches (2)4-15 cm, basal branches appressed, without axillary pulvini, distal branches ascending, occasionally lax or drooping distally.

appressed.

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.

unequal, brown to chestnut, 1-veined, awned;

lower glumes 6-12 mm, awns 2-5 mm;

upper glumes 13-18 mm, awns 3-6 mm;

calluses 0.4-0.8 mm;

lemmas 9-13 mm long, narrowing to a poorly defined beak 1-2 mm long and 0.2—0.3 mm wide, glabrous, tan to brown, junction with the awns not conspicuous;

awns usually unequal, not disarticulating at maturity;

central awns 15-30 mm, curved to semicircular at the base, horizontal to reflexed distally;

lateral awns 13-20 mm, at least 1/2 as long as the central awns, curved or loosely twisted at the base, straight and strongly divergent distally;

anthers 3, about 4 mm, yellow.

6-8 mm, tan to brown.

= 22.

= unknown.