This vegetation type is dominated by Potamogeton praelongus, a submerged aquatic macrophyte. It occurs in oligotrophic to mesotrophic water at depths of 20–120 cm, specifically in the lentic sections of rivers and in oxbows. In the Czech Republic it occurs naturally only at a few sites in eastern Bohemia. Historically it was recorded in Prague, and it was introduced in the Kokořínsko area.