Alder or ash-alder galleries of the banks of fast-flowing rivers and large brooks replacing the peri-Alpine Alnus incana galleries in hills of northern and western Europe. They are usually co-dominated by Alnus glutinosa, Fraxinus excelsior and Acer pseudoplatanus, accompanied by Acer platanoides, Ulmus glabra, U. laevis. Prunus padus is frequent in the undergrowth, shrubs include Ribes rubrum, R. uva-crispa, Corylus avellana; the herb layer comprises Stellaria nemorum, Impatiens noli-tangere, Aconitum vulparia, Allium ursinum, Geum rivale, Athyrium filix-femina, Dryopteris carthusiana, Matteuccia struthiopteris, Ranunculus platanifolius, Urtica dioica, Ranunculus ficaria, Primula elatior, Lamium galeobdolon or Filipendula ulmaria, Luzula sylvatica. The gallery may be enclosed within other forests or reduced to a thin line of alders along rivers traversing pastureland.