Rhizomatous. Stems to more than 2 m. Leaves all submerged, translucent, green to brownish, sessile, ovate to broadly ovate, 18-70 x 15-40 mm, obtuse to almost roundish and somewhat cucullate at apex, cordate and perfoliate at base, usually undulate, margin minutely dentate. Stipules to 1 cm, membranous, evanescent. Peduncles 3-10 cm. Spikes 14.5 cm. Fruitlets 24 mm, ± obovate. Fl. 6-8. Lakes, in fairly deep water, s.l.-2300 m.
N. Africa, Egypt, temperate Eurasia, N. America.