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.