Flora of North America species comparison

submersed or floating, rarely emersed; submersed phyllodial, flattened, 30–250 × 0.1–1.5 cm; floating with petiole flattened, to 40 cm, blade linear-ovate to ovate, rarely sagittate, to 3.5 × 0.5 cm; emersed with petiole 5–10 cm, blade linear-ovate to ovate, rarely hastate to sagittate, to 4 × 0.5 cm; stranded plants usually with expanded leaf blades.

submersed and emergent;

petiole triangular, 11.5–35 cm;

blade elliptic to ovate, 25–56 cm.

racemes, rarely panicles, of 4–10 whorls, floating to slightly emersed, 15–25 × 5–15 cm;

peduncles 10–200 cm;

bracts connate more than ¼ total length, lanceolate, 110 mm, delicate, not papillose; fruiting pedicels spreading to recurved, cylindric, 1.5–4.5 cm.

racemes or panicles, of 4–10 whorls, emersed, 8–25 × 5–36 cm;

peduncles to 76 cm;

bracts connate ¼ total length, lanceolate, 4–8 mm, papillose; fruiting pedicels ascending to spreading, cylindric, 1–4.5 cm.

to 3 cm diam.;

sepals spreading in staminate, erect in pistillate, enclosing flower or fruiting head;

filaments dilated, ± equaling anthers, glabrous;

pistillate pedicellate, without ring of sterile stamens.

to 3 cm diam.;

sepals appressed to spreading;

filaments slightly dilated, shorter than anthers, glabrous;

pistillate pedicellate, without ring of sterile stamens.

heads 0.7–1 cm diam.;

achenes obovoid, abaxially keeled, 5 × 2.5 mm, beaked;

faces not tuberculate, wings 0–3, ± entire, glands 0–1;

beak lateral, erect, 1 mm.

heads 0.7–1 cm diam.;

achenes obovoid, abaxially keeled, 1.2–1.5 × 0.7–1.1 mm, beaked;

faces not tuberculate, wings 1, ± entire, glands 0–1;

beak lateral, erect, 0.1–0.3 mm.

= 22.