Flora of North America species comparison

60-120 cm, stiffly erect, unbranched.

70-150 cm tall, 3-6 mm thick at the base, erect, rarely branched.

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 cauline;

sheaths usually longer than the internodes, remaining intact at maturity, glabrous or appressed pilose;

collars glabrous or pilose at the sides;

ligules less than 0.5 mm;

blades (10)15-30 cm long, 1.5-3 mm wide, flat at the base, involute toward the apex, straight to somewhat lax at maturity, glabrous abaxially, yellowish-green when fresh, drying stramineous or darker.

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.

paniculate, (15)20-55 cm long, 2-4 cm wide;

nodes glabrous or with short, straight hairs;

primary branches (4)5-20 cm, appressed to narrowly ascending, without axillary pulvini, naked below, with 5-15 overlapping spikelets distally.

appressed.

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.

6-10(12) mm, 1-veined, 1-keeled, awns less than 4 mm, brownish;

lower glumes from 3/4 as long as to 1 mm longer than the upper glumes;

calluses 1-2 mm;

lemmas 5-8 mm, often reddish-mottled, apices not strongly twisted, junction with the awns not evident;

awns about equally thick, divergent, spirally contorted at the base but usually not with distinct coils, not disarticulating at maturity;

central awns 10-15 mm;

lateral awns 8-13 mm;

anthers 3, about 2 mm.

4-5 mm, chestnut brown.

4-5 mm, chestnut-colored.

= unknown.

= unknown.