Flora of North America species comparison

(3)10-50(80) cm, often highly branched above the base.

60-100 cm, erect, unbranched.

cauline, glabrous;

sheaths shorter than the internodes, not disintegrating into threadlike fibers;

ligules 0.4-1 mm;

blades 2-14 cm long, 1-2.5 mm wide, flat to involute.

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.

panicles, 5-15(20) cm long, 0.5-3 cm wide, often interrupted below;

nodes glabrous or with straight, less than 0.5 mm hairs;

primary branches 1-4 cm, erect to ascending, without axillary pulvini, with 3-8 spikelets.

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.

crowded.

appressed.

unequal, 1-veined, acuminate;

lower glumes 4-8 mm;

upper glumes 6-11 mm;

calluses 0.5-0.8 mm;

lemmas 6-9 mm, slightly keeled, midveins scabrous, junction with the awns not evident;

awns not disarticulating at maturity, flattened and straight to somewhat curved at the base, central rib flanked by equally wide pale wings;

central awns 7-15(20) mm;

lateral awns somewhat shorter, occasionally only 1-2 mm;

anthers 3, 0.3-0.7 mm.

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.