Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: crustose, at least partially endolithic, verruculate verrucules: scant, tiny or lacking,; perithecial warts subspherical with the base constricted, to 0.7 mm broad surface: (if visible) black, sometimes a paling of the substrate is only visible prothallus: absent Perithecia: single in the verrucule, up to 0.5 mm broad involucrellum: black carbonaceous and constricted below, algae visible in lower portion, subcompound in the sense of Swinscow, dark reddish brown; hymenium: interior I+ blue asci: saccate, 2-spored ascospores: ellipsoid, dark brown, muriform, up to 8-septate transversely and 3-septate longitudinally, 33-62 x 18-33 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on calcareous rocks, shales or sandstones; altitudes for western specimens range from 900 to 2800 m World distribution: western North America Sonoran distribution: scattered throughout Arizona and southwards into Sonora.