Oak-dominated forest (mainly Quercus robur and Quercus petraea but also other regional species) of acid soils through the Atlantic and continental regions, where European beech (Fagus sylvatica) is a potential competitor and extending northwards into the boreal zone, where Scots pine (Pinus sylvestris) increasingly figures in the canopy. Associated floras are generally rather poor but show some regional distinctiveness and towards the very humid western Atlantic seaboard have extraordinary richness of ferns and cryptogams.