Altitudinal distribution: subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a species with thalli recalling those of a sterile P. acetabulum, but with a different secondary chemistry (major substance: salazinic acid), older parts of thalli sometimes with isidioid warts; rather loosely attached to siliceous rocks, often with a low content in calcium, and there also overgrowing mosses and soil layers; widespread in Eurasia but rare, with two records from the Western Alps (France).
