Flora of North America species comparison

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.

submersed, phyllodial, lenticular, 5–40 ´ 0.1–0.4 cm, or rarely floating;

petiole terete, 2.4–4 cm;

blade linear-lanceolate to ovate, 1–2.5 ´ 0.3–1.5 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.

racemes, of 2–7 whorls, floating, 2–11 ´ 1.5–4.5 cm;

peduncles 5–40 cm;

bracts connate more than ¼ total length, subulate, 1.5–4.2 mm, delicate, not papillose; fruiting pedicels recurved, cylindric to club-shaped, 0.2–1.1 cm.

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.

0.4–1.2 cm diam.;

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

filaments dilated, longer than anther, glabrous; pistillate pedicellate, occasionally with ring of sterile stamens.

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.

heads 0.55–0.8 cm diam.;

achenes oblanceoloid, abaxially keeled, 2 ´ 1.5 mm, beaked;

faces not tuberculate, wings 1–2, crenate, glands 0–1;

beak lateral, erect, 0.2–0.4 mm.

= 22.