Alyxoria subelevata (Nyl.) Ertz & Tehler
=Opegrapha subelevata (Nyl.) Nyl.
Opegrapha varia var. subelevata Nyl.
Opegrapha subelevata (Nyl.) Nyl.
Thallus crustose, very thin to thin, slightly cracked, dirty whitish, greyish white, greyish. Apothecia usually numerous in the form of lirelles, arranged and as if raised in relief over the whole thallus, short, unbranched, more or less misshapen and very angular with the wider center (aspect of amoeba!), 1-2.6 x 0.3 -0.6 mm, disc very open and clearly visible, black but covered with a strong persistent bluish-gray pruina, thin rim, smooth and not pruinose, black. Spores long elliptical, hyaline (but may turn brown in decay), with a gelatinous layer 1-1.5 µm thick, 3-septate, 20-23 x 6-7 µm according to the literature; 16-20 x 4.5-6 µm according to our measurements. No characteristic color reactions. Saxicolous species found on limestone or not very acidic rocks, the mortar of the walls, the slightly limestone schists, etc. in damp areas and in the shade. N.B Species reminiscent of Alyxoria (Opegrapha) varia but saxicolous.