This vegetation forms small stands dominated by Potamogeton polygonifolius, which possesses both natant and submerged leaves. In mires, this species can occur in a terrestrial growth form without submerged leaves. It occurs in oligotrophic to mesotrophic, usually 5–20 cm deep water of submontane brooks and fishpond margins with peat accumulation. This association has an oceanic distribution range in Europe, and in the Czech Republic it occurs only at a few sites in the westernmost part of the country.