Atlas of North European vascular plants
Hultén & Fries 1986
597 Salix arctica Pallas
This variable, mainly arctic species can be divided into, at least, subsp. arctica in Eurasiatic and N. American arctic-subarctic areas and subsp. crassijulis (Trautv.) Skvorts. in E. Asia and northwestern N. America. Their distribution areas overlap. Possibly also connected with the S. arctica complex (cf. Hultén, Circumpol. II, p. 38, 316), although not mapped here, are the subsp. torutosa (Ledeb.) Hult. from Altai eastwards into northwestern N. America and the two species sphenophylla Skvorts. in E. Asia and northwesternmost N. America and petrophila Rydb. in Rocky Mts. Their distribution is mapped in op. cit., map 30. S. arctica belongs to the circumpolar plants (op. cit., map 29).