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.

10-100 cm, 2-10 mm thick, erect, simple or sparingly branched basally;

nodes sericeous, pilose or glabrous;

internodes usually glaucous.

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 crowded basally;

sheaths rounded, glabrous or hirsute, hairs fragile, papillose-based, margins sometimes ciliate distally;

ligules 0.6-2 mm;

blades 4-23 cm long, 1-10 mm wide, erect to spreading, flat or sometimes involute (on sterile branches), often curling at maturity, glaucous, abaxial surfaces sometimes with prominent papillae along the midribs, bases rounded or narrowing to the sheaths, margins cartilaginous, ciliate basally, scabridulous elsewhere, apices 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.

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.

2.1-4.2 mm long, 0.8-1 mm wide, usually 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.

1.2-2.4 mm, 1/2 - 3/4 as long as the spikelets, attenuate;

upper glumes and lower lemmas similar, 7-11-veined, acuminate, extending 0.3-1.2 mm beyond the upper florets;

lower florets sterile;

lower paleas 0.8-2 mm;

upper florets 1.5-2.4 mm long, 0.7-1.2 mm wide, ovoid to ellipsoid, smooth, nigrescent.

panicles 7-31 cm long, 3-15 cm wide;

rachises glabrous, tending to break at maturity;

branches usually alternate, slender, stiff, ascending to divergent;

pedicels 1-15 mm, appressed.

= 36, 54.

= 18.