Lecanora chlarotera subsp. chlarotera forma rugosella (Zahlbr.) Poelt
Lecanora rugosa (Nyl.) Nyl. [non Ach.]
Lecanora rugosella Zahlbr.
Differs from the type by its apothecia bearing a brown disc, numerous and sometimes out of shape by contact, thallus edge typically strongly granulose to crenulated. Thallus and apothecia edges : C-, K+ yellow, Pd-. Ascospores largely ellipsoid to ovoid, simple, colourless, 12-15 x 7-8 µm according to our measurements. On bark of decideous trees, isolated or along forest edges. N.B. A continuum of all forms occurs with Lecanora chlarotera subsp. chlarotera forma chlarotera (see pictures).*