Description: Look for this species on the well-drained turfy soil of granitic rocky ledges and walls. It differs from other members of the Trapeliopsis tribe in the white to grey squamulose thallus (lobes to 1.5mm wide) compressed into a rubbery crust centrally, but more rosette-like near the circumference. Discs are common, brown-pink with an oft-sugared (pruinose) top. The thallus turns C+ red. In Ireland, the species is thinly distributed mostly near the sea.

Key Identification Features:

• Thallus C+ red, of little grey squamulose rosettes
• Discs common, small, brown to pink; granitic soils near the sea.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Trapeliopsis wallrothii at iNaturalist World Species Observations database.