Alder or ash-alder galleries of the banks of fast-flowing nonalpine rivers and large brooks of western, central and northwestern Europe. They are usually codominated by Alnus glutinosa, Fraxinus excelsior and Acer pseudoplatanus, accompanied by Acer platanoides, Ulmus glabra, Ulmus laevis. Prunus padus is frequent in the undergrowth, shrubs include Ribes rubrum, Ribes 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.