Synonyms: Dermatocarpon bachmannii Anders var. inundatum Klem.; Dermatocarpon leptophyllum auct.ital. p.p.; Dermatocarpon meiophyllum Vain.
Distribution: N - Ven, TAA, Lomb. C - Sar. S - Camp (Ricciardi & al. 2000).
Description: Thallus foliose-umbilicate, monophyllous, (4-)15-20(-30) mm wide, rather thick (0.4-0.8 mm thick when dry), attached by a central holdfast. Upper surface pale to dark brown; lower surface usually darker brown than upper surface, smooth or finely granulose. Upper cortex hyaline, except the brown outermost part, with an epinecral layer of compressed hyphae. Medulla white, of 2-4 μm thick hyphae; lower cortex colourless except the brown outermost part, consisting of 7-9 cell layers. Perithecia black, completely immersed, without involucrellum, the wall colourless except in the brown uppermost part. Hamathecium or periphyses and periphysoids, interascal filaments absent; hymenial jelly hemiamyloid. Asci 8-spored, clavate, the wall thickened above, not amyloid. Ascospores 1-celled, hyaline, ellipsoid, (11-)14-18(-23) x (5-)6-8(-10) μm. Pycnidia common, more or less spherical, black. Conidia bacilliform. Photobiont chlorococcoid. Spot tests: cortex and and medulla K-, C-, KC-, P-, UV-. Chemistry: no lichen substances.
Note: on periodically inundated siliceous rocks, especially in the splash zone of lake shores or along creeks, in seepage tracks on slightly sloping faces. For further information see Orange (1998).