Rinodina bischoffii (Hepp) A. Massal.
Thallus crustose thin, very variable, continuous or discontinuous, smooth or rugose, sometimes granular, whitish dirty, earthy, gray-brownish, greyish, no hypothallus. Apothecia lecanorines, usually numerous, sessile, 0.4-0.8 mm in diameter, disc flat then convex, dark brown then blackish, fine margin disappearing at the end, at first concolorous in the thallus then brownish. Utriform asci with 8 spores. Spores broadly elliptical, brownish (slate gray in KOH), with two compartments typically separated by an equatorial belt equal to 1/4 the size of the spore, 15-20 x 10-14 µm according to the literature, 15-22 (23 ) x 10-13 (14) µm according to our measurements. Photobiont: trebouxioid. No significant color chemical reactions. Saxicolous species coming on rocks or limestone well exposed to the sun.