This floodplain forest is dominated by Fraxinus angustifolia or Quercus robur, with frequent occurrence of Acer campestre, Carpinus betulus, Ulmus laevis and U. minor in the subcanopy and Crataegus laevigata in the shrub layer. The herb layer has a distinctive synusia of vernal geophytes and in summer is dominated by nutrient-demanding hygrophilous forest species, with participation of some species of wetlands and mesic forests. It occurs in broad floodplains of lowland rivers in southern Moravia, within the geographical range of Fraxinus angustifolia. These sites are wetter than those of the association Ficario vernae-Ulmetum campestris: before rivers were dammed they were flooded every year for several days to several weeks. Many stands originated from former woodland pastures, which were conducive to oak regeneration; in the current closed-canopy forests oak is being continuously replaced by ash. Also, trees of mesic sites are spreading due to bank stabilisation associated with streamflow regulation on major rivers.