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

Thallus: foliose, monophyllous, reniform to irregularly spreading, loosely attached at one point, occasionally suberect, 1-4(-6) cm in diam. lobes: broadly rounded to subirregular often distinctly monophyllous or cochleate, with sinuous, rarely notched or incised, thickened margins rolled under forming a definite ridge below upper surface: livid slate gray to gray-brown suffused red-brown when moist, pale gray to dull gray-brown or red-brown when dry, undulate, smooth or here and there punctate-impressed or irregularly wrinkled to subfaveolate, in parts glossy, otherwise dull, flabby when moist, papery when dry, with minute, white maculae forming a delicate marbling of upper surface when wet (x 10 lens), without isidia or phyllidia, erose-sorediate soredia: coarsely granular, gray-blue, in erose, linear marginal soralia or in scattered, rounded, pustular laminal soralia usually close to lobe margins, sometimes also developing in cyphellae on lower surface near margins medulla: white photobiont: cyanobacterial lower surface: pale yellowish buff to gray-brown, red-brown or dark brown, delicately to strongly wrinkled-ridged or striate near margins, elsewhere densely felted-tomentose; tomentum: shaggy, gray to brown-black cyphellae: sparse, widely scattered, rounded to irregular 0.5-1.5(-2) mm in diam., sunken in tomentum, sometimes pustular and with gray soredia, with very thin, sharply defined, slightly raised margins, with a white basal membrane Apothecia: not seen Pycnidia: rare, occasional to scattered near apices, immersed, ostiole dark red-brown, 0.05-0.1 mm in diam., punctate-impressed conidia: hyaline, bacilliform to slightly curved, 4-6 x 1 µm Spot tests: all negative Secondary metabolites: none detected. Substrate and ecology: on rocks amongst mosses in open forest habitats of moderate to high humidity, 3800 m World distribution: widespread though nowhere common, pantemperate, pantropical (at higher elevations) Sonoran distribution: rare and local in central California [San Mateo Co: San Francisco Watershed] and perhaps extending southwards into the Sonoran area.