Arthonia viburnea Müll. Arg.

Lichenised. Poorly known taxon.
Substrate: bark
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a species with minute, hemispherical to subglobose, black ascomata and 5-septate ascospores (15-18 × 4.5-6 μm); apparently reported only from the type locality in France, where it was found on branches of Viburnum lantana.
France: Haute-Savoie;