Thallus: continuous, dull, superficial on the substrate, brownish photobiont: a trentepohlioid alga Perithecia: hemispherical, black, semi-immersed in the thallus, 0.2-0.5 mm diam. involucrellum: black, absent below the hamathecium; true exciple: colorless to violet-black hamathecium: composed of nearly unbranched pseudoparaphyses, not anastomosing; filaments: c. 0.5-1 µm wide, not inspersed with oil droplets asci: cylindrical, c. 70-100 x 6-10 µm, with 8, irregularly arranged ascospores ascospores: hyaline, long-fusiform, 7 (-11)-septate with eusepta, (35-) 45-50 (-70) x (3-) 3.5-4.5 (-6) µm; walls: not ornamented, without a gelatinous sheath Spot tests: all negative, UV negative Secondary metabolites: none detected. Substrate and ecology: on bark of e.g. Quercus World distribution: pantemperate or possibly nearly cosmopolitan Sonoran distribution: only found on the Channel Islands (California), where it seems to be rather common, according to the numerous collections. Notes: This species has been incorrectly reported as Porina hibernica P. James and Swinscow (syn. Zamenhofia hibernica (P. James and Swinscow) Clauz. and Roux), which, according to Harris (1995) is not known from America.