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.

emersed;

petiole triangular, erect to ascending, 6.5–51 cm;

blade sagittate, rarely hastate, 1.5–30.5 × 2–17 cm, basal lobes equal to or less than remainder of blade.

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, rarely panicles, of 3–9 whorls, emersed, 4.5–28.5 × 4–23 cm;

peduncles 10–59 cm;

bracts connate more than or equal to ¼ total length, elliptic to lanceolate, 3–8 mm, delicate, not papillose; fruiting pedicels spreading, cylindric, 0.5–3.5 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 4 cm diam.;

sepals recurved to spreading, not enclosing flower or fruiting head;

filaments cylindric, longer 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 1–1.7 cm diam;

achenes oblanceoloid, without abaxial keel, 2.5–3.5 × to 2 mm, beaked;

faces not tuberculate, wings absent, glands (0–)1(–2);

beak lateral, horizontal, 1–2 mm.

= 22.

= 22.