Rhizomatous, aquatic perennial herb, with submerged and floating leaves. Stem terete, to 3 m long; turions recorded. Stipules convolute. Submerged leaves petiolate; blade lanceolate, 6–12 cm long, 1.2–3 cm wide, tapered at base, acute to obtuse at apex, 9–13-veined. Floating leaves petiolate; blade ovate to ±circular, rarely broadly lanceolate, 4–8 cm long, 3–5.5 cm wide, cordate, auriculate to rounded at base, obtuse at apex, coriaceous, 21–35-veined. Inflorescence a terminal spike, emergent, dense, to 5 cm long. Peduncles erect, recurved when fruiting. Fruit laterally compressed, 3–3.5 mm long (including beak), with 3 distinct, ornate, narrow, crenulate keels and a prominent beak.
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