Bagliettoa marmorea (Scop.) Gueidan & Cl. Roux
Amphoridium marmoreum (Scop.) Baroni
Verrucaria marmorea (Scop.) Arnold
Verrucaria purpurascens Hoffm.
Thallus endolithic, purple, purple-blue, notably towards perithecia where it may form a ring, prothallus dark brown, very conspicuous in case of mosaics. Perithecia immersed in the substratum, apices flat, reaching the same level as the thallus, leaving empty minute wells after falling, 0.2-0.3 mm diam., involucrellum absent. Ascospores simple, broadly ellipsoid to ovoid, colourless, breakable, 13-30 x 9-15 µm according to the literature, 20-25 x 12-15 µm according to our measures. Pycnidia sometimes numerous, visible as minute black dots. Oil droplets present within medulla. Absent from our prospection area, heliophile, mediterranean trends, on well-lit calcareous rocks. See Bagliettoa cazzae, paler pink, sterile, on shaded calcareous rocks.*