Description: This non-lichenised ‘bark-pimple’ species with an ill-defined thallus has rounded hemispherical discs but is unusual in its spores which can range from three- to seven-septate. Only one other member of the genus A. subcerasi has spores three-septate but in that species the spores never range beyond this number. A. platypyrenia is not common. It has been collected mostly from ivy bark. In Ireland, it has been recorded from County Kerry.

Key Identification Features:

• Thallus not discernible, discs persistently rounded, spores three- to seven-septate
• Recorded growing on ivy (Hedera) bark.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Arthopyrenia platypyrenia at iNaturalist World Species Observations database.