Flora of North America species comparison

emersed or submersed; submersed leaves phyllodial, flattened, 30–70 cm, rarely widening into blade; emersed leaves phyllodial, flattened, or petiole triangular, 34–50 cm, blade linear to elliptic, rarely hastate to sagittate, 5–15 × 0.6–12 cm, basal lobes when present shorter than remainder of blade.

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

rare stranded plants without expanded leaf blades.

racemes, of 2–8 whorls, emersed, 8–10 × 2–6 cm;

peduncles 10–115 cm;

bracts connate more than or equal to ¼ total length, ovate, 3–6 mm, delicate, not papillose; fruiting pedicels absent.

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.

to 3 cm diam.;

sepals recurved, not enclosing flower;

filaments dilated, shorter than anthers, pubescent;

pistillate sessile to subsessile, without ring of sterile stamens.

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.

heads 1–1.7 cm diam.;

achenes obovoid to oblong, abaxially keeled, 2–3 × 1.3–1.6 mm, beaked;

face not tuberculate, wings 1–2, ± entire, glands 1;

beak lateral, recurved, 0.8–1.4 mm.

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.

= 22.