Atlas of North European vascular plants
Hultén & Fries 1986
1672 Euphrasia arctica Lange subspp. arctica and borealis (Towns.) Yeo
These two subspecies are restricted to NW. Europe. Subsp. arctica seems to occur only on Orkney, Shetland and the Faeroes. Subsp. borealis is known from W. Nor way, Britain and Ireland (Fl. Eur. 3/1972, p. 262) and France (probably extinct; Yeo in Bot. J. Linn. Soc. 77 /1978, p. 263).