Flora of North America species comparison

11-110 cm, erect to decumbent;

nodes shortly hirsute or glabrous.

30-150 cm tall, 3-7 mm thick, compressed, spongy, glabrous, decumbent and rooting at the lower nodes in shallow water;

nodes glabrous;

internodes glabrous, smooth.

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 shorter than the internodes, not keeled, glabrous or sparsely hispid distally;

ligules 1-4 mm;

blades 10-40 cm long, 5-15 mm wide, flat, glabrous, contracted basally, attenuate distally, apices acute.

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.

10-25 cm long, 5-17 cm wide, shortly exserted or included basally;

primary branches 4-12 cm, ascending to spreading, secondary and higher order branches confined to the distal 2/3, pedicels 1-4 mm, sharply 3-angled, ascending to appressed.

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

3-4 mm long, 0.8-2 mm wide, lanceolate.

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.

0.5-0.9 mm, 1/5 – 1/3 as long as the spikelets, rounded, glabrous, truncate, weakly 1-3-veined;

upper glumes and lemmas subequal, glabrous, 9-11-veined, veins prominent, apices acute to accuminate;

lower paleas about 2/3 as long as the lower lemmas;

lower florets sterile;

upper florets 2-2.7 mm, narrowly ellipsoid, smooth, shiny, yellowish.

= 54.