Description: This dark-brown to purple-brown ‘scribble-lichen’ seeks out the most deeply shaded acid (siliceous) rocks in steep, rocky woodland where it occurs alongside other shade-seekers such as O. gyrocarpa and O. zonata. O. saxigena is non-sorediate with short, squat, slit-like discs (0.5-1.2mm diam.) and three-septate spores. Extreme western Ireland.

Key Identification Features:

• Brown thallus and short discs (lirellae) with slit barely exposed; three-septate spores
• On shaded acid rocks in wooded valleys, never on limestone.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Gyrographa saxigena at iNaturalist World Species Observations database.