This association comprises acidophilous oak forests of wet habitats, dominated by Quercus robur, less frequently by Q. petraea agg., and accompanied by Betula pendula and B. pubescens. The shrub layer contains Frangula alnus in most stands, but it rarely reaches high cover. The herb layer is usually dominated by Molinia arundinacea, less frequently by M. caerulea or Carex brizoides. It contains generalist acidophilous species, but also some species of wet meadows. These forests occur in flatlands or shallow depressions with deep, nutrient-poor soils that tend to be wet from autumn to spring but dry out in summer.