Bacidina caligans (Nyl.) Llop & Hladun

Syn.: Bacidia caligans (Nyl.) A.L. Sm., Lecidea caligans Nyl., Woessia caligans (Nyl.) Sérus. & Diederich
Lichenised.
Substrate: calciferous rocks, bark
Altitudinal distribution: submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus)
Note: this species belongs to the B. arnoldiana-group, but is sorediate and generally sterile; it has a mild-temperate to Mediterranean distribution and is mainly calcicolous (sometimes occurring also on mosses and mortar, rarely on bark at the base of trunks), in shaded and humid situations at relatively low elevations; hitherto known only from the Western Alps, but, being easily overlooked, it could be more widespread.
France: Haute-Alpes; Alpes-Maritimes; Isère; Var;