Pertusaria pseudocorallina (Lilj.) Arnold forme fertile

    Thallus crustose, rather thick, very tightly appressed to the substratum, 10-15 cm across, cracked to areolate, sterile areoles distributed mostly towards the edges, verrucose with -sometimes although rarely- brownish isidia, clavate, fertile areoles with large globose warts, irregular, coating the areole, dotted with black apothecia, pale grey-pink, pale ochre-pink, cream-pink, margin with greyish thin prothallus, or with a cheloid scar in case of mosaics. Apothecia immersed in the large fertile warts, leaving discs visible only as black dots, 1-2(3-5) per fertile wart. Ascii 2-spored. Ascospores simple, thick walls, 125-250 x 50-85 µm. Photobiont: Chlorococcoid. Thallus: C-, K+ yellow > soon red, KC+ yellow mixed with red, P+ golden yellow. This fertile morph is rather rare and confined, on siliceous rocks notably vertical walls near the seashore, very rare inland.

_ If isidia on sterile warts are absent this morph is rather difficult to distinguish from Pertusaria pertusa var. rupestris which is K+ yellow and with thallus whitish without pink tinge.