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.

15-100 cm tall, 0.5-1(2) mm thick, sprawling to erect, without cormlike bases, freely branching and rooting from the lower nodes;

nodes prominent, glabrous or pubescent;

internodes not succulent, pilose.

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 than the internodes, rounded, hairs papillose-based;

collars pilose;

ligules 0.2-0.5 mm;

blades 2-7 cm long, 5-20 mm wide, 4-6 times longer than wide, lanceolate, thin, flat, sparsely to densely pilose, hairs papillose-based, bases asymmetrically cordate to subcordate, lower margins ciliate, papillose.

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.

4-24 cm, almost as wide as long, diffuse, partially included or exerted;

primary branches to 10 cm, alternate, ascending to reflexed, branching in the distal 2/3;

pedicels 9-20 mm, threadlike.

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.

1-1.4 mm long, 0.5-0.6 mm wide, not secund, lanceoloid to narrowly ovoid, plano-convex in side view, sparsely pubescent.

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.

0.4-0.8 mm, 1/3 – 1/2 as long as the spikelets, 1-3-veined, subacute;

upper glumes 0.8-1.2 mm, arising 0.2 mm above the lower glumes, 3-5-veined;

lower florets sterile;

lower lemmas 0.1-0.2 mm longer than the upper glumes, 3-5-veined;

lower paleas 0.5-0.8 mm, hyaline;

upper florets 0.8-1.2 mm long, 0.4-0.6 mm wide, finely rugose, lemmas strongly convex.

= 36, 54.

= 18.