50 Athyrium distentifolium Tausch

Syn.: A. alpestre (Hoppe) Rylands

This moderately variable, arctic-montane species occurs disjunctly in Eurasia and N. America. In eastern and western N. America it is represented by var. gaspense Fem. and var. americanum Butters, respectively. The species s. lat. belongs to the amphiatlantic plants (Hultén, Amphi-atl., p. 242 and map 223), hut its distribution has also a circumpolar character. Cf. also Meusel et al. 1965, map p. 15.