Description: Although presumed extinct in Ireland this should not deter the lichen hunter. In fact, it is virtually identical to A. norvegicum (described elsewhere) in all external features other than the discs that grow to twice the size (to 1.2mm diam.). Its habitat requirements in Ireland are unknown; the species has become extinct in the UK. Smooth-barked trees in ravine woodlands appear to be its European headquarters.

Key Identification Features:

• Like A. norvegicum in all external features; it is currently believed extinct
• Differs from the above in the larger discs and in some details of the disc tissues.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthothelium spectabile at iNaturalist World Species Observations database.