Arthonia apotheciorum (A. Massal.) Almq.
Arthonia clemens auct. brit. non (Tul.) Th. Fr.
Parasite lichen of Lecanora dispersa apothecia.
Thallus absent. Apothecia developing in the host apothecia, initially as small black round-shaped dots 0,1-0,3 mm in diam., and then increasing in size up to be contiguous blackening the whole host apothecia. Ascospores long, ellipsoid, uni-septate, 9-15 x 3-5 µm. C-, K-, P-. This species grows as parasite of Lecanora dispersa : Lecanora albescens, etc., apothecia. Aspect more or less similar to Arthonia varians growing on Lecanora rupicola, that has narrower spores.*