Atlas of North European vascular plants
Hultén & Fries 1986
1641 Veronica serpyllifolia L. subsp. humifusa (Dicks.) Syme
This arctic-montane subspecies belongs to the discontinuous circumpolar plants (Hultén, Circumpol. Il, p. 260 and map 252). Cf. also Meusel et al. 1978, map p. 396.