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

Thallus: foliose, small, 1-1.5 cm in diam., adnate lobes: +flattened (0.5-1 cm wide and up to 1 cm long), imbricate or separate; tips: rounded to subtruncate upper surface: gray or blue-gray to brown when dry, bluish gray when wet, isidiate isidia: laminal, peltate medulla: white, with +loosely interwoven hyphae photobiont: Nostoc lower surface: white, with anastomosing pale, smooth, flattened veins, rhizinate rhizines: pale to medium brown, irregular, bushy or penicillately branched Apothecia: not seen in Sonoran material, also elsewhere rare, up to 7 mm in diam. asci: cylindrical, Peltigera-type, 8-spored ascospores: colorless to pale brown, acicular, 3(-5) septate, 50-60 x 4-5 µm Pycnidia: not seen in Sonoran material Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on soil in dry habitats World distribution: temperate and boreal regions of North America, Europe and Asia, South America, Australia, and Hawaii Sonoran distribution: rare in central Arizona (1600 m). Notes: Peltigera lepidophora is easily distinguished by its laminal, peltate isidia, but its small thalli are easily overlooked.