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.*