Placocarpus melanophthalmosus Cl. Roux & Gueidan

Lichenised.
Substrate: siliceous rocks
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 recently-described species resembling P. schaereri, but parasitic on Rhizoplaca melanophthalma, with smaller squamules, a thinner medulla, and smaller ascospores with a thinner halo.