This association is characterized by both the fen species with boreal distribution, considered to be glacial relicts, and the species requiring stable water regime and deep peat. The vegetation consists of short fen sedges (including Carex davalliana on some sites), tall fen sedges (C. diandra and C. lasiocarpa), broad-leaved wetland plants (Menyanthes trifoliata) and brown mosses such as Campylium stellatum and Scorpidium cossonii. The substrate is a deep water-saturated peat, without precipitated calcium carbonate. The association contains many rare and endangered species such as Eriophorum gracile. Pedicularis palustris and Hamatocaulis vernicosus. It occurs at a few sites in the Doksy region of northern Bohemia, the Bohemian-Moravian Uplands, and northern Moravia.