Incertae sedis Agonimia tristicula Growth type squamulose Chemical results negative Overgrows moss on mortared walls and calcareous soils, occasional on bark of base-rich trees. 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. Asci 1-2 spored, the spores colourless becoming pale yellow-brown, muriform 70-120 x 25-50 µm. Microscope photograph below. Similar: A. octospora. Corticolous, less flattened squamules. Asci 8-spored

Microscope photograph

Agonimia tristicula
Wool, Pamphill and Wareham, Dorset. February 2013, November and December 2016