Lecidea subtrullissata Müll. Arg.

Lichenised. Poorly known taxon.
Substrate: siliceous rocks
Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a species of unclear relationships recalling a Porpidia in habitus, with a thin, whitish, rimose to areolate thallus, large sessile apothecia, the discs with a bluish-grey pruina when young, a dark hypothecium, a c. 70 µm high hymenium with sparsely branched paraphyses, and very small, ellipsoid ascospores; on iron-rich siliceous sandstone; in the study area so far only known from the Western Alps (France).
France: Haute-Savoie;