Atlas of North European vascular plants
Hultén & Fries 1986
1440 Pyrola grandiflora Radius
This species is sometimes regarded as a subspecies of P. rotundifolia (no. 1439). It cannot always be told apart from P. rotundifolia. The population in the Fennoscandian mountains is distinguished as P. norvegica Knaben or P. rotundifolia subsp. norvegica (Knaben) Hyl., probably a result of introgression between P. rotundifolia and P. grandiflora. The species is mentioned among the amphi-atlantic plants by Hultén, Amphi-atl., p. 142 and map 124, but might just as well be regarded as a circumpolar species. Cf. also Meusel et al. 1978, map p. 324.