Flora of North America species comparison

submersed, phyllodial, lenticular, to nearly terete, 12–53 × 0.3–0.7 cm;

rare stranded plants without expanded leaf blades.

emersed;

petiole 5-ridged, ascending to erect, 24.5–60 cm;

blade sagittate, 11.5–26.5 × 0.8–15 cm, basal lobes longer than remainder of blade.

racemes, of 2–7 whorls, floating or emersed, to 16 × 4 cm;

peduncles 13.5–28 cm;

bracts connate more than ¼ total length, ovate to lanceolate, 1.5–2 mm, delicate, not papillose; fruiting pedicels spreading to reflexed in flower and fruit, cylindric, 1.5–6.5 cm.

racemes, rarely panicles, of 5–17 whorls, emersed, 20–37 × 5–27 cm;

peduncles 25–96 cm;

bracts connate more than or equal to ¼ total length, lanceolate, 6.5–15 mm, delicate, not papillose; fruiting pedicels spreading, cylindric, 1.5–4.4 cm.

1.5–5 cm diam.;

sepals spreading in staminate, appressed to spreading in flower and fruit in pistillate, often enclosing flower or fruiting head;

filaments dilated, longer than anthers, glabrous;

pistillate pedicellate, without ring of sterile stamens.

to 3 cm diam.;

sepals recurved to spreading, not enclosing flower;

filaments cylindric, shorter than anthers, glabrous;

pistillate flowers pedicellate, without ring of sterile stamens.

heads 0.4–0.6 cm diam;

achenes oblanceoloid to obovoid, not abaxially keeled, 1.5 × 1 mm, beaked;

faces not tuberculate, wings absent, glands absent;

beak lateral, erect, 1.1 mm.

heads 0.9–1.5 cm diam;

achenes oblanceoloid, abaxially keeled, 1.2–2.5 × 0.8–1.6 mm, beaked;

faces tuberculate, wings absent, glands 0–1;

beak lateral, erect, 0.1–0.6 mm.