Description: In appearance, this smooth-bark species is probably closest to Arthonia elegans (described elsewhere), and several rare Arthonia species which possess the spore character of having an enlarged upper cell. The non-frosted discs are often star-shaped, with arm-like projections, but a microscope will be required to view the three-to-four-septate spores with a size range of 16-26&

371;m long. It occurs on hazel, holly, rowan and oak mainly. North and south-west Ireland.

Key Identification Features:

• Similar to A. elegans but with star-shaped discs bearing arm-like projections; smooth-barked trees
• The discs are never frosted over; spores in the range16-26ųm long with an enlarged upper cell.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthonia stellaris at iNaturalist World Species Observations database.