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

Primary thallus: squamulose, soon disappearing; squamules: 7-10 mm long, 5-7 mm wide, irregularly lobed to deeply laciniate podetia: (9-) 14-32 (-60) mm tall, 1-2 mm thick, glaucous gray to brown, dichotomously branched; axils: open, more rarely closed; tips: subulate, never cup-forming surface: corticate, cortex thinning above base, scattered areolate to slightly raised-verruculate, giving rise to podetial squamules; squamules: abundant, 2-5 mm long, bearing granular material beneath, at apices granular-sorediate Apothecia: infrequent, 0.5-2.0 mm wide, brown ascospores: oblong to ellipsoid, 11-17 x 4-6 micro meter Pycnidia: common, at tips of podetia, urn-shaped, constricted at base, with hyaline gelatin conidia: 5-8 x 1-1.5 micro meter Spot tests: K- or K+ dingy yellow to dingy brown, C-, KC-, P+ red, UV- Secondary metabolite: fumarprotocetraric acid. Habitat and ecology: on thin soil on road cuts and among mosses, usually terricolous, not seen on wood, in mainly coastal and oceanic habitats World distribution: Asia, Australasia, Europe, North America, South America and sub-Antarctica Sonoran distribution: Baja California and southern California. Notes: Cladonia scabriuscula is morphologically similar to C. furcata. The podetia of C. scabriuscula can have sorediate tips, but intermediate forms may have scurfy to verruculose tips, and these characteristics may intergrade. Most of specimens from western North America are characterized by scurfy, non-squamule-forming bits of cortex at the apices. Cladonia scabriuscula is more frequent than C. furcata in the area, but has been overlooked in the past. In some populations these species are almost impossible to distinguish, but the details of their total distributions in the world are poorly known.