Flora of North America species comparison

septate or not septate.

emersed;

petiole 5-ridged, ascending to erect, 24.5–60 cm;

blade sagittate, 11.5–26.5 × 0.8–15 cm, basal lobes longer than remainder of blade.

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, rarely panicles, of 5–17 whorls, emersed, 20–37 × 5–27 cm;

peduncles 25–96 cm;

bracts connate more than or equal to ¼ total length, lanceolate, 6.5–15 mm, delicate, not papillose; fruiting pedicels spreading, cylindric, 1.5–4.4 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 recurved to spreading, not enclosing flower;

filaments cylindric, shorter than anthers, glabrous; pistillate flowers 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 0.9–1.5 cm diam;

achenes oblanceoloid, abaxially keeled, 1.2–2.5 × 0.8–1.6 mm, beaked;

faces tuberculate, wings absent, glands 0–1;

beak lateral, erect, 0.1–0.6 mm.