Physconia muscigena (Ach.) Poelt var. bayeri (Nádv.) Poelt

Syn.: Physcia bayeri Nádv.
Lichenised.
Substrate: calciferous soil, acidic soil (mostly on siliceous substrata), living mosses, plant debris
Altitudinal range: from the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron) to the alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)
Note: a variety differing from typical Ph. muscigena in the yellowish medulla, the colour intensifying with K; ecology comparable to that of the type variety, but also found on mossy faces of both calcareous and volcanic rocks, and perhaps more frequent at lower elevations; not generally distinguished, and therefore distribution in the Alps insufficiently known.
Austria: Tirol; Kärnten; Steiermark; Italy: Valle d'Aosta;