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.

50-200 cm, mostly erect and sterile, glabrous, often rooting from the lower nodes if submerged.

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.

usually glabrous, or pilose or hirsute at the lowermost sheath, especially distally;

ligules shorter than 1 mm;

blades 8-35 cm long, 5-15 mm wide, ascending or spreading, abaxial surfaces glabrous, adaxial surfaces usually scabridulous or pubescent, bases slightly narrowed, margins scabrous, apices long-tapering.

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.

10-30 cm long, less than 1 cm wide;

branches mostly short, appressed-ascending, with fascicles of congested spikelets; ultimate branchlets 1-sided;

pedicels 0.2-1.8 mm.

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.

2-2.8 mm, subsessile, lanceoloid, slightly laterally compressed, glabrous, acute.

about 1/2 as long as the spikelets, slightly keeled along the midveins, 3-veined, acute;

upper glumes and lower lemmas similar, glumes slightly shorter than the lemmas, faintly keeled on the back, acute;

lower florets staminate;

lower paleas subequal to the lower lemmas;

upper florets 2-2.5 mm, 2/5 to almost as long as the spikelets, narrowly ellipsoid;

upper lemmas relatively thin, flexible, pale, acuminate, clasping the paleas only at the base.

= 18.

= 36, 40.