Flora of North America species comparison

11-110 cm, erect to decumbent;

nodes shortly hirsute or glabrous.

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

shorter than the internodes, greenish to purplish, glabrous or with papillose-based hairs, ciliate on 1 margin, glabrous on the other;

collars hirsute;

ligules 1.5-3.5 mm, of hairs;

blades 3-30 cm long, 3-30 mm wide, flat, usually hirsute or sparsely pubescent, hairs papillose-based, sometimes glabrous, bases rounded to cordate-clasping, margins ciliate, cilia papillose-based, 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.

9-30 cm long, 5-8 cm wide, erect or nodding, partially included to well-exserted, rachises glabrous or sparsely hispid basally;

primary branches usually alternate to opposite, divergent, secondary branches and pedicels confined to the distal 2/3;

pulvini inconspicuous;

secondary branches appressed;

pedicels 9-27 mm, 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.

1.9-4 mm long, 0.8-1 mm wide, ovoid to almost spherical, often reddish-brown, glabrous, veins prominent, scabridulous, apices abruptly acuminate.

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

1.3-2.4 mm, 1/2 - 3/4 as long as the spikelets, 3-5-veined;

upper glumes 1.8-3.3 mm, 7-11-veined;

lower florets sterile;

lower lemmas similar to the upper glumes, 9-veined;

lower paleas 0.4-0.9 mm;

upper florets 1.5-2.4 mm long, 0.4-0.8 mm wide, ellipsoid, smooth or conspicuously papillate, shiny, stramineous, often with a lunate scar at the base.

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.

= 36, 40.