Lecidea siderolithica Müll. Arg.

Syn.: Lecidea nigrogrisea Nyl.
Lichenised. Poorly known taxon.
Substrate: siliceous rocks, metal-rich siliceous rocks
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a species of the L. fuscoatra-group developing small thin crustose thalli reacting C+ red (gyrophoric acid), with smaller ascospores than in L. fuscoatra; on siliceous rocks at mid-elevations; in the study area so far known only from the Western Alps (France).
France: Haute-Alpes; Haute-Savoie;