Syn.: Amundsenia approximata (Lynge) Søchting, Arup & Frödén, Caloplaca vitellinula (Nyl.) H. Olivier f. approximata Lynge
Lichenised.
Substrate: calciferous rocks, intermediate rocks (such as calciferous schists)
Altitudinal range: from the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a species with a strongly reduced, pale yellow thallus, bright orange apothecia, and narrowly ellipsoid ascospores with thin septa, perhaps closely related to C. cacuminum; on schists containing various amounts of calcium; based on a type from Novaya Zemlya and widespread from the Arctic to high elevations in the boreal zone; in the Alps so far known only from a single locality.
