These marshes are dominated by Eleocharis palustris, rarely also by E. mamillata. They occur in wetlands with a mineral bottom, often rich in calcium or brackish. Stands of E. palustris tolerate significant fluctuations of water table. They can be flooded for a long time in winter, and even in summer for a period of 2–4 weeks, but they can also survive periods of soil desiccation. Stands of E. mamillata are less tolerant to this kind of periodic desiccation, and are correspondingly distributed mainly in precipitation-rich areas. This association occurs from the lowlands to the mountain areas of the Czech Republic.