Dwarf oligo-mesotrophic annual communities of recently emerged muds and sands of the nemoral, boreonemoral and boreal regions. Terrestrial forms of amphibious species and annual species are frequent. A dynamic habitat, and several aspects can occur during the vegetation cycle. If the substrate is sufficiently wet, and also in advanced successional stages, the moss layer is abundant. Typical species are Juncus bufonius, Cyperus fuscus, Cyperus flavescens and other species from vegetation of class Isoeto-Nanojuncetea.
Rare communities colonising the fluid muds of drying ponds of nemoral, boreonemoral, boreal, and, locally, steppic, Palaearctic Eurasia, characterised by Eleocharis ovata, Eleocharis carniolica, Carex bohemica, Lindernia procumbens, Scirpus supinus, Limosella aquatica, Cyperus fuscus, Peplis portula, Juncus tenageia, Elatine hexandra, Elatine hydropiper, and Coleanthus subtilis; the latter species has a highly disjunct distribution, principally in western France, the Czech Republic and adjacent southeastern Germany and northern Austria, the Lake Ladoga region of Russia and Amurland.