Rhizomatous, aquatic annual or short-lived perennial with submerged and floating leaves. Stem terete, to 3 m long; turions not recorded. Stipules convolute. Submerged leaves sessile, lanceolate, 3–9 cm long, 0.4–1.5 cm wide, tapered at base, tapered or acute at apex, 5–9-veined. Floating leaves petiolate; blade ovate to ±circular, rarely broadly lanceolate, 2–7 cm long, 0.7–3 cm wide, auriculate or truncate or rounded at base, obtuse at apex, coriaceous, 9–25-veined. Inflorescence a terminal spike, emergent, dense, to 3 cm long. Peduncles erect, recurved when fruiting. Fruit laterally compressed, 3–3.5 mm long (including beak), with 3 prominent and tuberculate keels, with prominent beak.
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