Thallus: continuous, immersed in the substrate upper surface: pale gray, smooth; photobiont: absent Perithecia: hemispherical, black, semi-immersed in the thallus, 0.2-0.5 mm diam. ascomatal wall: black, absent below the hamathecium hamathecium: mostly unbranched pseudoparaphyses, not anastomosing; filaments: up to c. 3 µm wide below, not inspersed with oil droplets asci: cylindrical, c. 50-75 x 10-15 µm, with 8, uniseriately arranged ascospores ascospores: hyaline, long ellipsoid to fusiform, 1-septate with a median euseptum, 15-18 x 4.5-6 µm, with median endospore thickenings in each cell; walls: not ornamented, without a gelatinous sheath Spot tests: all negative, UV negative Secondary metabolites: none detected. Substrate and ecology: on bark of various woody plants World distribution: tropical to temperate areas of western North America Sonoran distribution: commonly collected in southern California, including the Channel Islands. Notes: The species was originally described from the region, and among the studied material was an isotype, which may be the only remaining type specimen. It was not studied by Harris (1973 & 1995a) but agrees with his concept of the species, except that it is non-lichenized. The specimen reported from California as Arthopyrenia cinereopruinosa (Schaer.) A. Massal. probably also belongs to this species.