Schaereria fuscocinerea (Nyl.) Clauzade & C. Roux

    Thalli crustose, spreading, 3-6 cm across, may form mosaics, areolate, areoles angular, smooth, flat to convex, 0.3-0.8 mm diam., brown-chocolate, brown-greyish, brown-darkish, greyish, blackish. Apothecia immersed within areoles, 0.3-1 mm diam., irregular, disc flat to slightyly convex, dark-brown, blackish, exciple thin, inconspicuous, excluded finally. Ascospores simple, ellipsoid, colourlesss, 10-16 x 5-8 µm. Photobiont: Trebouxia. Cortex: C-, K-, KC-, Pd- ; Medulla: C+ pink-red, K-, KC+ red, Pd-. On higly exposed and windy siliceous  rocks (with a rather smooth surface) of cliffs, often together with  Rhizocarpon geographicum or Rhizocarpon richardii. N. B. This species is rather dark and, based on its aspect, difficult to distinguish from Aspicilia or Rhizocarpon and probably is understated since its aspect may suggest other common species.*