Altitudinal distribution: alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)
Note: a species resembling P. clandestina in the endolithic thallus and the ascomata immersed in pits, but with larger, narrow ascospores with 5-7 transversal septa and a single, incomplete longitudinal septum; on limestone in Eastern and Central Europe, with a single record from the Eastern Alps (Austria).
