Atlantic forests of the British Isles, western Belgium and northwestern France, mostly on more or less water-retaining soils, characterized by a diverse tree layer, dominated by Quercus robur and rich in Fraxinus excelsior, and by an herb layer rich in species of the group of Hyacinthoides non-scripta, in particular Narcissus pseudonarcissus, Gagea spathacea, Tamus communis, Primula vulgaris, Luzula forsteri. Allium ursinum, Primula elatior, Ranunculus ficaria, Anemone nemorosa, Lamium galeobdolon characterise variants linked to soil acidity and hygromorphy.