Anamorph: conidiomata pycnidia, minute, (20-) 30-50 (-60) µm diam., scattered, immersed but becoming erumpent at the apices, subglobose, black, opening by an irregular pore. Conidiomatal wall composed of 1-3 layers of polyhedral to rounded cells, mainly 3- 5 µm diam., dark brown and thick-walled. Conidiogenous cells lining the internal wall of the pycnidial cavity, (3.5-) 4-5 (-6) x (2-) 3-3.5 (-4) µm, shortly ± cylindrical to ampulliform, proliferating percurrently or with a single annellation. Conidia 2-3.5 (-4) µm, subglobose to somewhat polyhedral, not markedly truncated at the base, brown, ± smooth to verruculose.
Teleomorph: not known.
Assessed by Woods & Coppins (2012) as of Least Concern.
Causing necrotic patches on many members of the Parmeliaceae, including species of Evernia, Flavoparmelia, Hypogymnia, Hypotrachyna and Parmotrema. Records on other hosts may need re-appraisal.
Throughout the British Isles.