This association is dominated by the narrow-leaved, submerged species Potamogeton obtusifolius, which is accompanied in some sites by another narrow-leaved species, P. acutifoliusá. It occurs in mesotrophic to naturally eutrophic, clear, 30–150 cm deep water. The habitats include small fishponds, oxbows, alluvial pools, flooded sand pits, brooks and lentic sections of rivers. It is a rare vegetation type, which occurs at scattered sites from the lowlands to submontane areas in the Czech Republic, and has retreated in the past decades due to intensification of fishpond management and increased water turbidity.