Thelidium zahlbruckneri Servít

Lichenised. Poorly known taxon.
Substrate: calciferous rocks
Altitudinal distribution: submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus)
Note: a species with a thin, brown to greyish-brown thallus, hemispherically protruding perithecia (to c. 0.15 mm in diam.) lacking an involucrellum, and 1-septate, ellipsoid ascospores (to c. 15 µm long); on pebbles of calcareous sandstone; only known from the type locality in the Eastern Alps (Austria).
Austria: Niederösterreich (incl. Wien);