Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, continuously or irregularly forming rosettes, 3-8 cm wide, loosely adnate, lobate lobes: irregular, 2-4 mm wide, elongate; lobe tips: usually subrotund, frequently dissected marginally in teeth-like pattern upper surface: usually medium to dark brown or red-brown, rarely gray-brown, shiny or somewhat pubescent, isidiate isidia: initially cylindrical but becoming flattened, 0.1-0.2 mm diam.; without soredia but frequently with regeneration squamules that may cover the whole thallus medulla: white photobiont: the cyanobacterium Nostoc lower surface: dark brown to black but paler at the margins, pubescent or tomentose but not papillate Apothecia: common, immersed on lower surface at tips of lobes, orbicular, up to 8 mm diam., cup-shaped, sessile; dorsal surface: scabrid and often markedly honey-combed; margin: prominent with thalloid, pectinate rim; disc: dark brown; exciple: hyaline or light brown, 20-30 µm thick; epithecium: brown or brownish yellow; hypothecium: hyaline asci: 8-spored ascospores: subfusiform; 3-septate, 20-27 x 6-8 µm; wall: thick, light brown Pycnidia: marginal, immersed, punctiform, 0.09-0.15 mm diam. conidia: rod-shaped, 3-4 x 1-2 µm Spot tests: upper surface: K-, C-, KC-, P-; medulla K+ pale yellow or K-, C-, KC-, P- Secondary metabolites: upper cortex with unknown brown pigment; medulla with triterprenes 7α acetoxyhopan-22-ol, hopane-7α, 22-diol and an accessory unknown. Habitat and ecology: on acidic rocks among mosses in moderate shade and tree trunks in moist canyons at mid- to high elevations, most common in spruce-fir regions World distribution: Africa, Australasia and throughout the Northern Hemisphere, where it occurs in boreal and north temperate regions and extends south along the west coasts in maritime influenced regions Sonoran distribution: central and SE Arizona and the Sierra Madre Occidental region of Chihuahua.