Flora of North America species comparison

emersed or submersed; submersed leaves phyllodial, flattened, 30–70 cm, rarely widening into blade; emersed leaves phyllodial, flattened, or petiole triangular, 34–50 cm, blade linear to elliptic, rarely hastate to sagittate, 5–15 × 0.6–12 cm, basal lobes when present shorter than remainder of blade.

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 2–8 whorls, emersed, 8–10 × 2–6 cm;

peduncles 10–115 cm;

bracts connate more than or equal to ¼ total length, ovate, 3–6 mm, delicate, not papillose; fruiting pedicels absent.

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 3 cm diam.;

sepals recurved, not enclosing flower;

filaments dilated, shorter than anthers, pubescent;

pistillate sessile to subsessile, 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 1–1.7 cm diam.;

achenes obovoid to oblong, abaxially keeled, 2–3 × 1.3–1.6 mm, beaked;

face not tuberculate, wings 1–2, ± entire, glands 1;

beak lateral, recurved, 0.8–1.4 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.

= 22.