Flora of North America species comparison

5-200 cm tall, 0.4-3 mm thick, decumbent to erect, commonly geniculate to ascending, rooting at the lower nodes when in water, simple to divergently branched from the lower and middle nodes, usually succulent, slightly compressed, glabrous;

nodes usually swollen, sometimes constricted on robust plants, glabrous;

internodes glabrous, shiny, pale green to purplish.

2-8 cm, erect-spreading;

nodes 1-2, hispid;

internodes pilose, hairs papillose-based.

compressed, inflated, sparsely pubescent near the base, elsewhere mostly glabrous, sparsely pilose, or hispid, hairs sometimes papillose-based, margins or throat ciliate, with papillose-based hairs;

ligules 0.5-2 mm;

blades 10-65 cm long, 3-25 mm wide, glabrous or sparsely pilose, often scabrous near the margins, midribs stout, whitish.

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.

4-40 cm, diffuse, lax, with a few spikelets;

branches to 15 cm, alternate or opposite, occasionally verticillate, ascending to spreading, stiff, scabrous;

pedicels 1-6 mm, sharply 3-angled, scabrous, expanded to cuplike apices, appressed mostly to the abaxial side of the branches.

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.

1.8-3.8 mm long, 0.7-1.2 mm wide, ellipsoid to narrowly ovoid, light green to red-purple, glabrous, acute to acuminate.

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

0.6-1.2 mm, 1/4 - 1/3 as long as the spikelets, 0-3-veined, obtuse to acute;

upper glumes and lower lemmas similar, exceeding the upper florets by 0.3-0.6 mm, 7-9-veined;

lower paleas vestigial to almost as long as the lower lemmas;

lower florets sterile;

upper florets 1.4-2.5 mm long, 0.7-1.1 mm wide, narrowly ellipsoid, smooth, shiny, stramineous to nigrescent, with pale veins.

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, 54.