Lecanora rupicola (L.) Zahlbr. subsp. subplanata (Nyl.) Leuckert & Poelt. Disque des apothécies C+ jaune.
Thallus relatively thick, cracked to areolate, greyish, greyish-white, slightly bluish-grey. Apothecia numerous, close together, often deformed by contact, at first included in the thallus then slightly raised but not sessile, disc yellowish-white, pale yellowish-brown, but appearing bluish-gray by a strong bloom, margin sinuous more or less angular, sometimes crenellate. Thallus: C-, K+ yellow, KC+ yellow, yellow-orange, P+ weak yellow; margin of apothecia: C+ yellow, disc of apothecia: C+ yellow by bloom. Common taxon everywhere on siliceous rocks.
N.B. Taxon replaced at the seaside by: Lecanora rupicola subsp. rupicola morpho rupicola Disque des apothécies C+ orange.