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.

10-150 cm, slender, wiry, erect at first, ultimately decumbent, sprawling, glabrous, often with purple dots and streaks, branching extensively at the base, rooting at the lower nodes.

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.

often shorter than the internodes, loose, glabrous, margins short-ciliate;

ligules 0.2-0.5 mm, membranous, erose, ciliate;

blades 5-20 cm long, 3-10 mm wide, thin, flat, glabrous on both surfaces, margins scabridulous, apices long-acuminate.

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.

5-30 cm, nearly as wide as long;

branches few, capillary, with a few spikelets distally;

pedicels 0.5-10 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.

1.7-2.2 mm long, about 1 mm wide, ellipsoid or obovoid, glabrous, faintly veined, subacute or obtuse at the apices.

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.

0.3-0.8 mm, reduced, acute;

upper glumes and lower lemmas subequal or the glumes shorter, distinctly verrucose, with hemispheric warts;

upper florets 1.6-2 mm long, about 1 mm wide, grayish-brown, dull, minutely papillose, acute.

= 36, 54.

= 36.