OregonFlora species comparison

rhizomes absent; tubers present.

fibrous, septate or not.

short caudices.

emersed;

petioles ascending to erect; to 50 cm;

blades sagittate, 1–30 × 2–15 cm.

basal, emersed, floating or submersed; simple, linear to sagittate, palmately veined.

emersed, with 3–9 whorls, 4–25 cm;

peduncles 10– 55 cm; lowest inflorescence node with 3 pistillate flowers;

pedicels cylindrical, 0.5–3.5 cm.

scapose;

umbel-, raceme-, or panicle-like;

branches whorled.

to 4 cm in diameter;

sepals recurved to spreading;

petals without spot at base.

monoecious, dioecious, or bisexual; radial;

sepals 3, generally green, generally persistent;

petals 3, generally bigger than sepals, white or pink;

stamens 6–many;

pistils 6–many; free or fused at the base.

heads 1–2 cm in diameter;

achenes oblanceolate, 2–3.5 mm;

wings absent;

beaks lateral or horizontal, 1–2 mm.

achenes, compressed, beaked.

endosperm absent in mature seed.