Flora of North America species comparison

20-150 cm tall, 2-4 mm thick, erect or spreading, sometimes decumbent and rooting from the lower nodes, distal portion sometimes floating in shallow water.

50-100 (150) cm tall, 3-8 mm thick, spongy, erect to decumbent and rooting at the lower nodes.

glabrous, keeled;

ligules 5-15 mm;

blades 5-25 cm long, 3-10 mm wide, both surfaces smooth.

finely scabridulous, not or weakly keeled;

ligules 4.5-12 mm, lacerate;

blades 12-30 cm long, 3.5-11 mm wide, both surfaces sometimes scabridulous, adaxial surfaces sometimes sparsely papillose.

10-50 cm long, 2-3 cm wide;

branches 3-5 cm, paired or solitary, usually appressed to ascending, divergent at anthesis, with 1-4 spikelets;

pedicels 0.8-20 mm.

20-40 cm long, 2.5-8 cm wide;

branches 4.2-14.7 cm, appressed to ascending, with 3-8(10) spikelets;

pedicels 2-5 mm, scabrous.

(15)18-39 mm long, 1.7-3.3 mm wide, cylindrical and terete, except slightly laterally compressed at anthesis, rectangular in side view, with 8-16 florets.

9-20 mm long, 0.4-3 mm wide, cylindrical and terete, except at anthesis when slightly laterally compressed, rectangular in side view, with 6-15 florets.

broadly rounded to acute;

lower glumes 0.6-2.1 mm;

upper glumes 1.4-3.4 mm;

rachilla internodes 1-1.5 mm;

lemmas 2.6-4.5 mm, somewhat indented below the apical margins at maturity, veins raised, scabridulous to scabrous over and between the veins, prickles about 0.05 mm, midveins extending to within 0.1 mm of the apical margins, apices truncate to obtuse, crenulate;

paleas shorter than or equaling the lemmas, keels winged, tips parallel, intercostal region truncate or rounded, sometimes exceeding the keel tips;

anthers 3, 0.3-0.9 mm.

1.3-3.9 mm;

upper glumes 2.7-5 mm;

rachilla internodes 1.9-2.5 mm;

lemmas 5.2-8 mm, midveins extending to within 0.1 mm of the apical margins, scabrous over and between the veins, prickles about 0.05 mm, apices acute, usually entire;

paleas from shorter than to 0.6(1.5) mm longer than the lemmas, keels winged, apices bifid, teeth 0.1-0.4 mm, parallel to convergent, sometimes crossing when dry;

anthers 1.5-3 mm, usually purple.

2-3 mm.

= 40.

= 40.