Thelidium schibleri Zschacke

Lichenised. Poorly known taxon.
Substrate: calciferous rocks
Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a calcicolous species with a blackish-brown, thin thallus, semi-immersed ascomata (to 0.3 mm in diam.) with involucrellum reaching down about half of the perithecium, and 1-septate, broadly ellipsoid ascospores (to c. 45 µm long); only known from the type locality.
Switzerland: Graubünden;