Substrate: intermediate rocks (such as calciferous schists)
Altitudinal distribution: subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a species of the B. aethalea-group, characterised by small, grey thalli not reacting with K but typically with a I+ blue medulla; on stones and low siliceous rocks; based on a type from Northern Siberia; distribution in the Alps very insufficiently known.
