Rhizomatous. Stems often more than 1 m. Leaves floating and submerged. Floating leaves with a ± discoloured flexible joint and marginal folds at top of petiole immediately below lamina; petiole 5-18 cm; lamina thorne at distinct angle to petiole, broadly ovate to elliptic-ovate, 5-11 cm, obtuse at apex, truncate to subcordate at base, opaque, often shiny especially beneath, green to brownish. Submerged leaves reduced to long, narrowly linear phyllodes, often disappearing early. Stipules 3-9 cm, conspicuous, often fibrous-persistent. Peduncles 5-12 cm. Spikes 3.5-5 cm. Fruitlets c. 4 mm, obovoid. Fl. 5-8. Lakes, pools, 50-2350 m.
Almost throughout Europe, N.W. Africa, Caucasia, Siberia, Syrian Desert, Afghanistan, N. America.