Bryostigma muscigenum (Th. Fr.) Frisch & G. Thor

Syn.: Arthonia leucodontis (Poelt & Döbbeler) Coppins, Arthonia muscigena Th. Fr., Bryostigma leucodontis Poelt & Döbbeler
Lichenised.
Substrate: bark, living mosses
Altitudinal range: from the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a species with a strongly reduced thallus containing a chlorococcoid photobiont, and minute, hemispherical ascomata, sometimes confused with Arthonia apatetica; it grows on the bark of deciduous trees, but also on epiphytic bryophytes (e.g. Leucodon sciuroides) and on leaves in humid forests; widespread in the Alps, but probably often overlooked
Austria: Tirol; Steiermark; Germany: Oberbayern; Switzerland: Graubünden; St. Gallen; Schwyz; Unterwalden; Valais; Italy: Trentino Alto Adige; Lombardia; Valle d'Aosta;