Description: As its name implies this ‘scripture lichen’ is parasitic. It invades the thallus of both Aspicilia calcarea and A. contorta. The small, black, snaky, elongated discs (lirellae) are easy to see. It should not be confused with O. rupestris which grows mostly on Verrucaria species. Northern and central Ireland. It is absent from the south.

Key Identification Features:

• Parasitic on the thallus of Aspicilia calcarea and A. contorta
• Thin black discs (lirellae), singly or thinly scattered, not clustered.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Opegrapha parasitica at iNaturalist World Species Observations database.