Order: Agyriales Family: Agyriaceae
Species: Trapelia coarctata
Photos: On rocks. Gougane Barra, Cork, SW Ireland.
Identified by John Douglass
Very variable. Thin, +/- smooth, white, bluish-grey or pink-grey thallus with +/- contiguous areoles. Apothecia pink to red-brown, the thin white margins often excluded with age.
Abundant on siliceous rocks, stones, bricks, mortar, occasionally on consolidated clay. K-, C+ red, KC+ red, P-, UV+ whitish.
Similar: T. glebulosa and T. placodioides
Trapelia coarctata. August 2009