Flora of North America species comparison

60-120 cm, stiffly erect, unbranched.

60-100 cm, erect, 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;

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, 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, (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.

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.

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.

4-5 mm, chestnut brown.

6-8 mm, tan to brown.

= unknown.

= unknown.