Arthonia varians (Davies) Nyl.

     Parasite lichen of Lecanora rupicola apothecia.

     Thallus absent and only apothecia developing in the host apothecia hymenium as black spots, 0,3-1 mm in diam., variable in shape and covering more or less the host apothecia (but seldom the whole surface). Ascospores ovoid to oblong, 2-3-septate, 11-17 x 5-6,5 µm. Relativeley frequent on Lecanora rupicola apothecia and notably in the aerohaline zone. N.B. This species is rather simimar to Arthonia apotheciorum growing on the apothecia of  Lecanora dispersa.*