This vegetation, dominated by Bidens radiata, is confined to exposed fishpond bottoms, with an exception of rare occurrences in fish storage ponds and water reservoirs. It develops on deep, loamy, water-saturated mud, which is rich in nutrients but poor in base cations. In the Czech Republic its occurrences are concentrated to mid-altitudinal fishpond areas, while it is absent from dry lowlands and high mountain areas.