Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Thallus: foliose, 2-8 cm in diam., adnate, subdichotomously to irregularly lobate lobes: irregular, elongated, +plane, separate, 3-7 mm wide, (90-)200-350 µm thick; apices: rotund, entire to irregularly cut and isidiate, occasionally upturned upper surface: usually dark brown but sometimes medium gray, shiny, strongly ridged periclinally isidia: scattered to dense, usually laminal but sometimes marginal, cylindrical to clavate, simple or branched, concolorous with the thallus or darker internal anatomy: with upper and lower cortices consisting of a single layer of irregularly isodiametrical cells 5-9 µm in diam., internally with loosely interwoven chains of Nostoc and hyphae lower surface: pale to medium brown, wrinkled, with dense white tomentum of cylindrical hairs up to 1 mm long Apothecia: rare, laminal, sessile, 0.5-0.8 mm wide disc: light brown to more usually yellow-brown or red-brown, concave to plane to convex margin: thalline, concolorous with the thallus, entire or isidiate exciple: euparaplectenchymatous, 25-70 µm centrally hymenium: hyaline below and thinly brown above, 90-125 µm tall; paraphyses: unbranched, c. 1.5 µm wide, slightly inflated apically; subhymenium: pale yellow, 35-45 µm thick asci: cylindrico-clavate, 8-spored ascospores: hyaline, muriform, 3-septate transversely, 1-septate longitudinally, ellipsoid, 23-29(-35) x 7-10 µm Pycnidia: not observed Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: particularly common on bark of soft-barked oaks and junipers at intermediate elevations World distribution: western North America Sonoran distribution: the most common Leptogium in Arizona. California, Baja California Sur, Sonora, Chihuahua and Sinaloa.