Flora of North America species comparison

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

internodes glabrous or pubescent, sometimes nearly lanose.

10-100 cm, erect to ascending, usually 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 or mostly cauline;

sheaths shorter or longer than the internodes, glabrous, not disintegrating into threadlike fibers at maturity;

collars glabrous, or sparsely pilose at the sides with straight hairs;

ligules less than 0.5 mm;

blades 4-25 cm long, 1-1.5 mm wide, tightly involute to flat, usually glabrous, sometimes scabridulous abaxially, gray-green, lax to curled at maturity.

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.

usually sparingly branched panicles, occasionally racemes, 3-30 cm long, 2-12 cm wide, with 2 or more spikelets per node;

nodes glabrous or with straight, about 0.5 mm hairs;

primary branches 3-6 cm, appressed to divaricate, varying sometimes within a panicle, stiff to flexible, bases appressed or abruptly spreading, usually without axillary pulvini.

appressed.

divergent or appressed, with or without axillary pulvini.

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.

usually unequal, lower glumes shorter than the upper glumes, sometimes subequal, light to dark brown or purplish, glabrous, smooth or scabridulous, 1(2)-veined, acuminate, unawned or awned, awns to 1 mm;

lower glumes 4-12 mm;

upper glumes 7-25 mm;

calluses 0.5-1.8 mm;

lemmas 6-16 mm, glabrous, scabridulous, or tuberculate, whitish to purplish, apices 0.1-0.8 mm wide, not beaked or the beak less than 3 mm, junction with the awns not conspicuous;

awns (8)13-140 mm, ascending to divaricate, not disarticulating at maturity;

central awns thicker than the lateral awns;

lateral awns (8)13-140 mm, usually subequal to the central awns, occasionally less than 1/3 as long as the central awns;

anthers 3, 0.7-2 mm.

6-14 mm, tan to chestnut.

= 22.

= 22, 44, 66, 88.