Flora of North America species comparison

10-75 cm, about 1 mm thick, simple or with erect basal branches;

nodes densely pilose, hairs ascending;

internodes glabrous or shortly pubescent distally.

50-140 cm tall, 1.5-2.5 mm thick, usually erect, rarely decumbent, firm;

nodes glabrous or puberulent;

internodes glabrous.

longer than the internodes, green to purplish, hispid, margins sparsely ciliate;

ligules 0.5-1.5 mm;

blades 3-32 cm long, 1-7 mm wide, ascending to erect, linear, narrowing basally, flat or the margins involute, surfaces sparsely hirsute or pilose (rarely glabrous), hairs near the base papillose-based, margins prominent, apices acute.

shorter than the internodes, glabrous or hispid, hairs papillose-based, rounded basally;

ligules 0.5-2 mm;

blades 10-30 cm long, 2-8 mm wide, flat, glabrous or sparsely hirsute on 1 or both surfaces.

5-45 cm long, 1-6 cm wide, at least 1/2 as long as the plants and 3 times longer than wide, open;

rachises glabrous;

primary branches usually alternate or subopposite, ascending to slightly divergent, secondary branches and pedicels attached to the distal 2/3;

secondary branches diverging;

pedicels 0.5-17 mm, ascending to appressed.

4-25(40) cm long, 3-14 cm wide, exerted, lax;

primary branches 3-14 cm, opposite and alternate, ascending, glabrous, branching in the distal M;

pedicels 1-4 mm, appressed or spreading.

2.5 - 3.7 mm long, 0.6-1.1 mm wide, narrowly ovoid, glabrous, acute;

lower glumes 0.8-1.3 mm, 1/3 – 1/2 as long as the spikelets, acuminate;

upper glumes 2.3-3.3 mm, 7-9-veined, exceeding the upper florets by about 0.6 mm;

lower florets sterile;

lower lemmas 2.2-2.7 mm, exceeding the upper florets by about 0.6 mm, 7- or 9-veined, apices scabridulous, pointed;

lower paleas absent;

upper florets 1.6-1.7 mm long, about 0.6 mm wide, usually smooth, usually pale, sometimes becoming dark at maturity.

2.5-3.5 mm long, 1-1.2 mm wide, narrowly ovoid to ellipsoid, glabrous, acute.

1-1.5 mm, about 1/3 as long as the spikelets, glabrous, 1-3-veined, acute;

upper glumes slightly exceeding the lower lemmas, glabrous, acute, scarcely separated from the lower lemmas;

lower florets staminate;

lower lemmas similar to the upper glumes;

lower paleas 2-3 mm, oblong;

upper florets 2-2.5 mm long, 0.8-1 mm wide, ellipsoid, widest below the middle, glabrous, smooth, shiny, apices lightly beaked.

= 18.

= 18, 36, 41, 42, 43, 45, 54, 63 (United States material apparently usually tetraploid, with 2n = 36).