Thelidium acrotellum Arnold

Lichenised. Poorly known taxon.
Substrate: calciferous rocks, siliceous rocks
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)
Note: on more or less calciferous rocks in upland areas; the species is not easy to distinguish from Th. minutulum, but has a colourless excipulum and a thin involucrellum; so far recorded from a few localities in the Alps.
Austria: Vorarlberg; Tirol; Steiermark; Oberösterreich; France: Savoie; Haute-Savoie; Italy: Trentino Alto Adige;