Melanelixia fuliginosa (Fr. ex Duby) O. Blanco & al.

    Thallus foliose, rosette-forming, to 10 cm diam., lobes appressed, 2-4 mm wide, flat, margin indented or crenulate, upper surface bright, dark brown to greenish when moist, blackish to sepia when dry, lower surface blackish with simple rhizines. The upper surface is densely covered with isidia that may darken almost the entire lobes, bright, cylindrical to coralloid, brown-black, thallus center potentially necrotic when old and finally vanishing (the overall aspect suggests a thick wool carpet). Apothecia rare, shortly stalked, 0.3-0.5 mm diam., disc dark brown-red, exciple upturned, slightly isidiate. Ascospores simple, 10-14 x 5-8 µm according to literature, 11-14 (15) x 5-8 (9) µm according to our measurements. Photobiont: trebouxioid. Cortex : K-. Medulla: C+ red, K+/- purple, KC+ red, Pd-. Not especially maritime, but common on siliceous rocks notably smooth rocks in the aerohaline zone. N.B. Not to be confused with Xanthoparmelia verruculifera that has a matt surface, larger isidia and different chemical reactions. Also in the collinean belt not to be mistaken with  Melanelia disjuncta that is C-, less intense black  and with conspicuous large globose mounds of grey isidia. N.B. Ther are some rock taxa that were incorporated in the Melanelixia fuliginosa subsp. glabratula, not entiredly black and with persitent green and brown-green colours. They don't have either isidia suggesting a wool carpet; see the Melanelixia gabratula rock form.*