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.

20-60 cm tall, 0.8-1.2 mm thick, shortly decumbent to geniculate basally, erect distally;

nodes glabrous;

internodes glabrous.

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.

shorter or longer than the internodes, rounded, smooth, glabrous;

ligules about 1 mm;

blades 5-15 cm long, 2-8 mm wide, flat, linear, glabrous or with a few marginal cilia near the base, bases contracted, apices long-acute.

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.

10-20 cm long, 6-12 cm wide, exserted or partially included;

primary branches alternate, ascending to strongly divergent, developing secondary branches in the basal 1/3 – 1/2, pedicels 4-9 mm, ascending.

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.

2.7-3.2 mm long, 1-1.2 mm wide, ovoid-ellipsoid, green tinged with purple, glaucous, glabrous, acute.

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.

0.7-1.1 mm, about 2/5 as long as the spikelets, acute to attenuate;

upper glumes and lower lemmas similar, equaling the spikelets, 11-13-veined, tapering to apiculate apices;

lower paleas 1-2 mm;

lower florets sterile;

upper florets about 2.2 mm, ellipsoid, smooth, shiny, yellow at maturity, apices acute.

= 36, 54.

= 54.