Flora of North America species comparison

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

2-8 cm, erect-spreading;

nodes 1-2, hispid;

internodes pilose, hairs papillose-based.

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.

rounded, much longer than the internodes, with prominent veins, hispid, hairs papillose-based;

ligules 0.2-0.4 mm, membranous, ciliate;

blades 1-4 cm long, 1-3 mm wide, flat or involute apically, glabrous basally, margins ciliate, cilia papillose-based.

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.

congested, partially included in the sheaths, less than 1.5 times longer than wide;

branches ascending, narrow;

primary branches appressed to the main axes, secondary branches and pedicels attached to the distal 2/3;

pedicels appressed, 1-2 mm.

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

2-2.2 mm long, 1-1.3 mm wide, plump-ellipsoid, glabrous.

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.

1.2-1.3 mm, acute to attenuate;

upper glumes and lower lemmas 2-2.2 mm, 7-9-veined, apices purplish, acute;

lower florets sterile;

lower paleas 0.2-0.4 mm;

upper florets 1.4-1.8 mm long, about 1 mm wide, broadly ovoid.

= 36, 40.