Verrucaria schaereriana Servít

Lichenised. Poorly known taxon.
Substrate: calciferous rocks
Altitudinal distribution:
Note: a species with a mainly endolithic to very thin epilithic, continuous, whitish to pale brown thallus, the black immersed perithecia (0.2-0.3 mm in diam.) hardly protruding and with a thin thalline annulus, without an involucrellum, more or less spherical with a conical ostiolar region, the wall black-brown in the uppermost part but pigmentation fading towards the base, 8-spored asci, and ellipsoid to fusiform, simple ascospores (23-36 × 12-15 μm); only known from the type locality in Switzerland.