Description: This pale grey, warted thallus with large, occasionally frosted, flat discs (to 3mm diam.) with a smooth margin (this, K+ yellow-red in squash) grows on well-lit acid rocks on heathy ground and coasts and on rock among the foothills of more mountainous areas. It is also Pd+ yellow. This group of lichens is always worth spot-testing in the field. Those reacting K+ yellow to red can then be collected for further evaluation. Thinly scattered, absent from central Ireland.

Key Identification Features:

• Discs with rim K+ yellow to red in section, Pd+ yellow
• Grey, warted thallus with large discs; dry foothills and coastal heath.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Porpidia platycarpoides at iNaturalist World Species Observations database.