Description: This small (to 2cm diam.), rosette-forming, orange, foliose lichen is easily told by the abundant orange discs with yellow margins. It grows on enriched tree bark and in the angles of twigs and is very common often near areas of intensive farming.

Key Identification Features:

• Its size, colour, rosette form and requirement for enriched or high pH bark, for example, elder, will help identify this species
• It can be separated from Candelaria concolor by its K (Potassium hydroxide) + purple reaction and from fertile Xanthoria candelaria by the absence of powdery fragmentation (soredia).

Original text submitted by Simon Davey

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

iNaturalist: Polycauliona polycarpa at iNaturalist World Species Observations database.