Bacidia scopulicola (Nyl.) A. L. Sm.
Thallus crustose, rather thick, 2-5 cm across, olive-green, fawn-brown to grey-green, warted and coarsely granular, ± covered with small short coralloid protuberances isidia-like or soredia-like. Apothecia often scarce or absent, 0.5-1.2 mm diam; discs flat at first but soon convex and often irregularly shaped or tuberculate, pale to dark brown (section orange), often with pink tinge; margin thick, wavy and usually darker than the discs, hymenium and hypothecium red-orange. Pycnidia present, red-brown, ± immersed in thallus. Ascospores lengthy fusiform and even acicular, 3- to 7-septate, 29-45 x 1,7-2 µm according to literature, 30-40 (50) x 1,5-2,5 µm according to our measures. Photobiont : Chlorophycea. Chemical spot tests negative. Rare, in crevices of ± vertical siliceous coastal rocks, in the xeric-supralittoral zone, protected by overhangs. Bacidia sipmanii grows in the same locations but has a thinner thallus (< 0,3 mm), smooth to hardly rough, warted, cracked and devoid of isidioid-like protuberances. N.B. Between these two species numerous intermediate morphs do exist. Here, we present them under the name of Bacidia scopulicola forma, of which thalli vary, according to locations, from isidiform or sorediform to more or less smooth and cracked.