Order: Verrucariales Family: Incertae sedis
Species: Agonimia tristicula
Photos: Glengarriff woods and mortared wall, Co. Cork, SW Ireland.
Photo left and immediately below identified by Andy Acton
Thallus of tiny, flattened green squamules, greyish-brown when dry, with minute papillae on upper surface. Very small, black, barrel-shaped apothecia are often half-hidden amongst the squamules.
Usually over moss on mortared walls and on calcareous soils. Occasionally on bark of base-rich trees; Acers, Elm and Ash.
Similar: Agonima octospora is corticolous, with smaller, less flattened squamules.
Agonimia tristicula March 2010 and December 2011