603 Salix nigricans Sm.

Syn.: S. myrsinifolia Salisb.

This polymorphic, boreal-montane species is mainly restricted to Europe. Besides the main type (subsp. nigricans), principally in N. Europe and the Alps, the map includes the subsp. apennina (Skvorts.) Borzi in the Apennines and the species S. jenisseensis Friedr. Schm. in N. Russia and Siberia. Probably both species overlap and hybridize considerably in N. Russia. In the Fennoscandian mountains S. nigricans subsp. borealis (Fr.) Flod. is distinguished (not mapped here, cf. Hultén, Atlas 1971, map 576). For further information on this critical complex in Europe, see int. al. Atlas Fl. Eur. 3/1976, maps p. 26 f.