Flora of North America species comparison

emersed or submersed, phyllodial or rarely dilated apically, flattened, 4–40 cm × 0.05–0.4(–0.5) cm.

submersed and emersed; submersed leaves absent or phyllodial, flattened, to 17 × 2 cm; emersed leaves with petiole triangular, 21–55 cm, blade hastate to sagittate, 2.5–17.5 × 0.6–22 cm, lobes longer than or equal to remainder of blade.

racemes, of 1–5 whorls, emersed, 2–20 × 1.5–12 cm;

peduncles 7–59 cm;

bracts connate more than or equal to ¼ total length, oblanceolate, 0.2–0.3 mm, delicate, not papillose; fruiting pedicels spreading, cylindric, 0.5–6 cm.

racemes or panicles, of 1–15 whorls, floating or emersed, 1.5–28 × 1.5–15 cm;

peduncles 15–47 cm;

bracts distinct or connate less than ¼ total length, lanceolate to elliptic, 4–34 mm, delicate, not papillose; fruiting pedicels recurved, club-shaped, 0.5–4.2 cm.

to 1.3 cm diam.;

sepals recurved to spreading, not enclosing flower;

filaments dilated, shorter than anthers, minutely tomentose;

pistillate pedicellate, without ring of sterile stamens.

2–5 cm diam.;

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

filaments cylindric, longer than anthers, glabrous;

pistillate pedicellate, with or without ring of sterile stamens.

heads 0.5–1 cm diam.;

achenes obovoid, abaxially keeled, 2.2–2.8 × 1.5–2 mm, beaked;

faces not tuberculate, wings 1–2, ± entire, glands 3–5;

beak lateral, incurved-erect, 0.2 mm.

heads 1.2–2.1 cm diam.;

achenes oblanceoloid, not abaxially keeled, 2–4.3 × 0.7–1.5 mm, beaked;

faces not tuberculate, wings absent, glands 1;

beak lateral, horizontal, 0.4–0.8 mm.