Description: This species occurs on the thallus of Graphis scripta. Discs are red-brown, variably shaped and sprinkled about the host thallus. The spores are two- or three-septate with an enlarged upper cell being a key feature. Smooth-barked trees. In Ireland, the species is widespread but local.

Key Identification Features:

• Red-brown discs bursting from below the bark; spores two- or three-septate with enlarged upper cell
• Growing on Graphis scripta on smooth-barked trees.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Arthonia graphidicola at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Arthonia graphidicola at iNaturalist World Species Observations database.