Flora of North America species comparison

60-120 cm, stiffly erect, unbranched.

10-100 cm, erect to ascending, usually unbranched.

basal or nearly basal;

sheaths shorter than the internodes, smooth and mostly glabrous abaxially, sometimes with a line of widely spaced, 0.5-1 mm hairs over the midvein, not disintegrating into threadlike fibers at maturity;

collars glabrous, sometimes with a few conspicuous hairs at the sides;

ligules 0.1-0.3 mm;

blades 15-50 cm long, 0.3-1 mm wide, tightly involute, stiff, yellow-green, abaxial surfaces villous on both sides of the midvein, at least on the basal portion, hairs 0.6-1.5 mm, adaxial surfaces densely scabrous or densely short pubescent.

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, 20-35 cm, 5-8 mm wide;

nodes glabrous;

primary branches 2-5 cm, appressed, without axillary pulvini, with 4-12 spikelets, spikelet-bearing to the base.

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.

subequal, glabrous, light brown or tan, usually 1(2)-veined, bifid and awned, awns 1.5-2.5 mm;

lower glumes 7-10 mm;

upper glumes 6-9 mm;

calluses 0.4-0.6 mm;

lemmas 6-9 mm, glabrous, light-colored when young, reddish when mature, column 1-2 mm, not twisted, junction with the awns inconspicuous;

awns (7)10-15(22) mm, subequal, usually horizontally spreading or curving downward, not disarticulating at maturity;

anthers 3, about 3 mm, reddish-brown.

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.

4-5 mm, chestnut brown.

6-14 mm, tan to chestnut.

= unknown.

= 22, 44, 66, 88.