Description: Thallus crustose, episubstratic, dark olive-brown to olive-black, subgelatinous when wet, continuous or rimose, smooth or usually with slightly raised punctiform warts or short ridges. Cortex scarcely differentiated, with a brown, pigment reacting K-; photobiont cells arranged in vertical rows; medulla with pillars of dark brown to black tissue often reaching the thallus surface. Perithecia black, largely immersed into up to 0.45 m wide thalline warts, projecting with the crater-like ostiolar region. Involucrellum thick reaching to base-level; exciple black, globose, 0.16-0.22 mm across; hamathecium of periphyses and periphysoids, interascal filaments absent; hymenial gel amyloid, I+ blue. Asci 8-spored, clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of an endotunica to form a delicate rostrum, Verrucaria-type. Ascospores 1-celled, hyaline, oblong-ellipsoid, 12-18 x 6-8 μm. Pycnidia immersed, with colourless wall and ostiole. Conidia rod-shaped. Photobiont chlorococcoid. Spot tests: thallus and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: a poorly known species of coastal calcareous rocks in the supralittoral zone, described from Liguria and also reported from southern France (Roux & coll. 2014).
Zschacke, H. (1934) Epigloeaceae, Verrucariaceae und Dermatocarpaceae. In: Dr. L. Rabenhorst‘s Kryptogamen-Flora, Band 9, Abt. 1, Teil 1. Akademische Verlagsgesellschaft, Leipzig, 695 pp. - Public Domain