Atlas of North European vascular plants
Hultén & Fries 1986
918 Parrya nudicaulis (L.) Boiss.
This polymorphic species has a wide arctic-montane distribution. Besides subsp. nudicaulis in northeastern Russia, Siberia and northwestern N. America some other subspecies are tentatively mapped, viz. subsp. septentrionalis Hult. in arctic Siberia and N. America, subsp. turkestanica (Korsh.) Hult. in C. Asia, subsp. interior Hult. in northwestern N. America, subsp. rydbergii (Botsch.) Hult. in the Rocky Mts. and a group of subspecies in the C. Asiatic mountains. The species s. lat. belongs to the discontinuous circumpolar plants (Hultén, Circumpol. Il, p. 42, 317f. and map 34).