Description: This lichenicolous lichen grows on the thallus of Peltigera hymenina. It is characterised by the scattered red-brown to blackish discs, the one-septate smooth colourless spores with upper cell shorter, absence of K+ purple pigments and presence of pycnidia. Currently there is a single record from County Fermanagh.

Key Identification Features:

• Red-brown discs (often edged with a white ring), one-septate spores with upper cell shorter and wider, no K+ purple pigments, pycnidia present
• Growing on the thallus of Peltigera hymenina.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthonia fuscopurpurea at iNaturalist World Species Observations database.