Microcalicium arenarium (Hampe ex A. Massal.) Tibell

Syn.: Calicium arenarium (Hampe ex A. Massal.) Hampe ex Körb., Coniocybopsis arenaria (Hampe ex A. Massal.) Vain., Cyphelium arenarium Hampe ex A. Massal.
Non- or doubtfully lichenised.
Substrate: siliceous rocks,
Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: on silicicolous lichens, soil, rootlets, decorticated stumps and algal colonies under overhangs of siliceous rocks, often together with Psilolechia lucida; probably more widespread in the Alps than the few records would suggest.
Italy: Trentino Alto Adige; Piemonte;