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.

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.

to 3 cm diam.;

sepals recurved, not enclosing flower;

filaments dilated, shorter than anthers, pubescent;

pistillate sessile to subsessile, 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.

= 22.