Miriquidica deusta (Stenh.) Hertel & Rambold

    Thallus crustose, tightly appressed to the substratum, areolate, areoles squamulose, 0.5-1.5 mm, more or less scattered on a conspicuous black prothallus, surface smooth and bright, edges irregular more or less crenulate and upturned, dark brown, brown-blackish, blackish, margin greyish, prothallus large, blackish to black, limits indistincly defined. Not fertile in our prospection area, elsewhere apothecia immersed in the thallus at first, then slightly prominent, 0.5-0.8 mm diam., disc  plane, black and not powdery, exciple thin and crisped, greyish, suggesting  a black mat covered with flowers or ice crystals. Ascospores ellipsoid, simple, colourless, 10-12 x 4-5.5 µm. Photobiont: Trebouxia. C-, K-, CK-, Pd-, I-. Rare, on large granite rocks on well-lit summits. N.B.1. Highly variable (described under different names and even genera), its frequency might be underestimated since at first it suggests a common Verrucaria... See also Lecidea fuscoatra of which the prothallus is not black and as developed, paler brown and usually fertile with apothecia slightly convex and powdery. N.B.2. This species preferentially seems to develop nearby yellow Rhizocarpons sp., similarly to Miriquidica intrudens which is parasite of yellow Rhizocarpons sp. but also nearby Lecidea fuscoatra. When young, might have a parasite stage.*