Flora of North America species comparison

emersed;

petiole 5-winged, 19–85 cm;

blade sagittate, 3–19 × 2.5–11 cm, basal lobes ± equal to remainder of blade.

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.

racemes, of 5–12 whorls, emersed, 10–29 × 3–5 cm;

peduncles 25–105 cm;

bracts distinct or if connate, then less than ¼ total length, lanceolate, 7–30 mm, papery, not papillose; fruiting pedicels spreading to ascending, cylindric, 0.3–2.3 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.

to 3 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.

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.

heads 1–2.2 cm diam.;

achenes obovoid, without abaxial keel, 2.1–3.2 × 1.4–2.3 mm, beaked;

faces not tuberculate, wings 0–2, ± entire, glands absent;

beak lateral, strongly recurved, 4–17 mm.

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.

= 22.

= 22.