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.

40-120 cm tall, 2-3 mm thick, decumbent to erect, branching from the base and the middle nodes;

nodes pilose, hairs spreading;

internodes hirsute, 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.

usually shorter than the internodes, hirsute, lower sheaths more so than those above, hairs papillose-based;

collars densely pilose;

ligules 0.5-4 mm;

blades 16-55 cm long, 0.5-14 mm wide, erect to ascending, abaxial surfaces hirsute, hairs papillose-based, adaxial surfaces densely pilose, midveins prominent and whitish, bases truncate, margins ciliate basally, apices attenuate.

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.

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.

2.6-3.4 mm long, 0.9-1.2 mm wide, ovoid, 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.

1.4-1.7 mm, to 1/2 as long as the spikelets, acute, 5-7-veined;

upper glumes and lower lemmas similar, exceeding the upper florets by 0.7-0.9 mm, 9-13-veined;

lower florets sterile;

lower paleas 0.5-1.3 mm;

upper lorets 1.7-2.3 mm long, 0.8-1.1 mm wide, smooth, ovoid.

panicles 7-35 cm long, 5-23 cm wide, about 1/2 as wide as long, shortly exerted or partially included, lax, open;

axillary panicles smaller, included basally;

primary branches diverging, lower branches solitary, upper branches solitary to subverticillate;

secondary branching primarily in the distal 1/3;

pedicels 1-4 mm, clavate, spreading to appressed.

= 36, 54.

= unknown.