in Roux & al., Bull. Soc. linn. Provence, 60: 172, 2009. Basionym: Verrucaria zamenhofiana Clauzade & Cl. Roux - Bull. Soc. Bot. Centre-Ouest, n. sér., nr. spéc. 7: 823, 1985.
Synonyms: Dermatocarpon compactum sensu Clauzade & Rondon
Distribution: N - Frl (vidi!), Ven (Nimis 1994), TAA, Piem (TSB 34795), VA (TSB 29429), Lig.
Description: Thallus crustose, areolate-subsquamulose, dark brown to almost black, 0.2-0.7 mm thick, parasitic on Staurothele areolata. Areoles 0.6-1.5 mm wide, finely crenulate-lobulate, crowded and fitting together like a puzzle, or with slightly overlapping margins, smooth and slightly glossy. Upper cortex well delimited, 20-25 µm thick, the uppermost cell layer with brown pigment, sometimes overlain with a very thin epinecral layer; medulla subparaplectenchymatous; lower cortex limited to the marginal part of areoles, 20-40 µm thick, paraplectenchymatous, pale brown, with granular inspersions, below with colourless, 3-4.5 µm thick rhizohyphae. Perithecia totally immersed; exciple subglobose, 0.18-0.27 mm across, the wall colourless; involucrellum lacking; paraphyses absent, substituted by simple periphyses. Asci 8-spored, clavate, bitunicate, with a thin tholus reacting I-, Verrucaria-type. Ascospores 1-celled, hyaline, broadly ellipsoid to subglobose, 10-12 x 9-10 µm. Pycnidia immersed, inconspicuous. Conidia bacilliform. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P- UV-. Chemistry: without lichen substances.
Note: a species with a crustose, dark brown thallus with incised to sublobate areoles, growing on taxa of the Staurothele areolata-group on slightly inclined to subhorizontal surfaces of calcareous rocks in upland areas; widely distributed in Europe and North America, as well as in the Alps, it is easy to overlook due to the thalli of host and parasite being concolorous. To be looked for in the central Apennines.