Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: thick, superficial, rimose-areolate upper surface: ochre to gray-brown, dull prothallus: absent Perithecia: immersed but appearing as prominent half-globose warts, dispersed; involucrellum: dark-brown, open, 20-40 µm wide; exciple: colorless below, pale brownish above; hamathecium: composed of persistent paraphyses, richly branched and anastomosed; periphysoids towards the inner side of the ostiole; periphyses absent; ostiole: dark-brown to blackish brown asci: cylindrical, 8-spored ascospores: colorless, muriform, with 7-11 lateral and 3 longitudinal septa, narrowly ellipsoid to subcylindrical, 35-47 x 14-19 µm Pycnidia: immersed conidia: filiform, colorless, 15-22 x 0.8-1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on sandstone and tuff in maritime influenced habitats World distribution: SW North America Sonoran distribution: southern California on San Nicolas Island and Baja California on Guadalupe Island. Notes: This species is characterized by its perithecia appearing as prominent half-globose warts, an open involucrellum and large colorless muriform ascospores. The subantarctic distributed Thelenella kerguelena is distinguished by its smaller and cylindrical ascospores.