Pertusaria rupicola forma coralloidea (Anzi) P. L. Nimis

    Thallus crustose, rather thick, more or less cracked to crazed, slightly verrucose, abundantly isidiate, isidia 1-2 mm high, 0.5-1 mm diam., apices globose, yellowish when dry, yellow-greenish when moist, prothallus usually inconspicuous, blackish. Suboceanic saxicolous species with mediterranean and coastal trends, on sloping or vertical walls of siliceous rocks. Photobiont: chlorococcoid. C+ orange, K+ yellow, KC+ yellow to orange, Pd-. N.B. Corresponds to the Pertusaria rupicola f. rupicola sterile form and sometimes thriving together (thalli with both forms may be found). See also Pertusaria corallina of which the thallus is whitish to pale grey and Pd+ orange.