Flora of North America species comparison

septate or not septate.

submersed and emergent;

petiole triangular, 11.5–35 cm;

blade elliptic to ovate, 25–56 cm.

basal, submersed, floating, or emersed, sessile or petiolate, sheathing proximally;

blade with translucent markings of dots or lines present or absent, basal lobes present or absent;

venation reticulate, primary veins parallel from base of blade to apex, secondary veins reticulate.

racemes or panicles, of 4–10 whorls, emersed, 8–25 × 5–36 cm;

peduncles to 76 cm;

bracts connate ¼ total length, lanceolate, 4–8 mm, papillose; fruiting pedicels ascending to spreading, cylindric, 1–4.5 cm.

scapose racemes or panicles, rarely umbels, erect, rarely floating or decumbent, whorled (forming racemes) or whorls branching (forming panicles), bracteolate.

to 3 cm diam.;

sepals appressed to spreading;

filaments slightly dilated, shorter than anthers, glabrous;

pistillate pedicellate, without ring of sterile stamens.

bisexual or unisexual, if unisexual, staminate and pistillate on same or different plants, hypogynous, subsessile to long-pedicellate;

sepals persistent, 3;

petals deciduous, 3, delicate;

stamens 0, 6, 9, or to 30, distinct;

anthers 2-loculed, dehiscing longitudinally;

pistils 0 or 6–1500 or more, distinct or coherent proximally, 1-loculed;

placentation basal;

ovules1–2.

achenes or follicles.

embryo U-shaped;

endosperm absent in mature seed.

heads 0.7–1 cm diam.;

achenes obovoid, abaxially keeled, 1.2–1.5 × 0.7–1.1 mm, beaked;

faces not tuberculate, wings 1, ± entire, glands 0–1;

beak lateral, erect, 0.1–0.3 mm.