Arthonia patellulata Nyl.

Syn.: Allarthonia patellulata (Nyl.) Zahlbr., Arthonia betuleti Nyl., Coniangium krempelhuberi A. Massal.
Lichenised.
Substrate: bark
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 cool-temperate to boreal-montane, probably circumpolar species found on smooth bark, mostly of Populus tremula; from the Alps there are only scattered records.
Austria: Kärnten; Germany: Oberbayern; Italy: Veneto; Lombardia; Piemonte;