Flora of North America species comparison

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.

submersed and floating, sessile, phyllodial, flattened, 50–250 × 0.4–1.5 cm;

rare stranded plants without expanded leaf blades.

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.

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

peduncles to 200 cm;

bracts connate less than or equal to total length, lanceolate, 0.4–0.8 mm, delicate, not papillose; fruiting pedicels spreading to recurved, cylindric, 1.5–4.5 cm.

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.

to 2.8 cm diam.;

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

filaments dilated, ± equaling anthers, glabrous; pistillate pedicellate, without ring of sterile stamens.

heads 1–1.7 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.

heads 0.7–1 cm diam.;

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

faces not tuberculate, wings absent, glands 0–1;

beak lateral, erect, 1 mm.

= 22.

= 22.