Flora of North America species comparison

(10)50-140 cm, stout, stiffly erect, branched from the middle and lower nodes;

lower nodes sericeous;

lower internodes sericeous, hairs papillose-based, upper internodes sometimes glabrous.

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

rounded, glabrous or sparsely to densely hispid, hairs not fragile and prickly, not causing skin irritation, margins ciliate;

ligules 1-3 mm;

blades 3-60 cm long, 2-12 mm wide, flat or involute, ascending, adaxial surfaces densely hirsute basally, less densely so elsewhere, bases attenuate, 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.

(4)15-40 cm long, (3)10-25 cm wide, about 1/3 – 1/2 as long as the plants, open, breaking at the base of the peduncles at maturity and dispersed as tumbleweeds, secondary branching mostly confined to the distal 1/3 of the primary branches;

rachises densely hispid or glabrous;

lower primary branches in whorls of 4-7, stiffly spreading, naked on the lower 1/2;

pedicels 3-20 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.

2-3 mm long, 0.8-1.2 mm wide, glabrous.

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

1-1.6 mm, 5-veined, acuminate;

upper glumes and lower lemmas similar, 2-2.8 mm, 7-9-veined, exceeding the upper florets by about 0.3 mm;

lower florets sterile;

lower paleas 1.4-2.2 mm;

upper florets 1.5-1.9 mm long, 0.7-1 mm wide, smooth, chestnut brown at maturity.

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.

= 36, 40.