Description: This lichen parasitizes another, so is lichenicolous. To find it, you’ll need to find the host Lecanora rupicola (described elsewhere). It only grows within the discs of L. rupicola which then blacken on invasion. The colourless spores are mostly two- to three-septate and between 11-17µm long. In Ireland it is only known from a few scattered records in the north and west.

Key Identification Features:

• Lichenicolous on the discs of Lecanora rupicola
• Spores colourless, broadly ellipsoidal, two- to three-septate.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthonia varians at iNaturalist World Species Observations database.