Description: This is the commonest of the three Irish representatives of this mainly tropical genus. In T. lepadinum the raised discs resemble barnacle-like warts scattered over a shiny, pale, grey-cream crust. It can be found mostly on the smooth bark of trees where there is a history of continuous canopy cover, but can also spread to rock.

Key Identification Features:

• Shiny, wrinkled, grey-cream crust
• The discs are pustules, barnacle-like in appearance, with pore-like openings.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Thelotrema lepadinum at iNaturalist World Species Observations database.