Hypocenomyce scalaris (Ach.) M. Choisy

Syn.: Biatora ostreata (Hoffm.) Th. Fr., Lecidea ostreata (Hoffm.) Schaer., Lecidea scalaris (Ach.) Ach., Lichen scalaris Ach., Psora ostreata Hoffm., Psora scalaris (Ach.) Hook.
Lichenised.
Substrate: bark, lignum, siliceous rocks
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a temperate to boreal-montane, circumpolar lichen found on acid bark, especially of conifers, but also on Castanea and on lignum, including charred wood; widespread and locally common throughout the Alps.
Austria: Vorarlberg; Tirol; Salzburg; Kärnten; Steiermark; Oberösterreich; Niederösterreich (incl. Wien); Burgenland; Germany: Oberbayern; Schwaben; Switzerland: Graubünden; Luzern; St. Gallen; Ticino; Uri; Vaud; Valais; France: Alpes-de-Haute-Provence; Haute-Alpes; Alpes-Maritimes; Isère; Savoie; Haute-Savoie; Vaucluse; Var; Italy: Friuli; Veneto; Trentino Alto Adige; Lombardia; Piemonte; Valle d'Aosta; Liguria; Slovenia: Alpine and Pre-Alpine Slovenia;