Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: foliose, 3-8 cm wide, loosely adnate, lobate lobes: irregular, 2-6 mm wide, elongate; apices: usually subrotund, entire or with small lobules upper surface: medium to dark brown, shiny or very slightly pubescent; without soredia or isidia but very rarely with regeneration squamules medulla: white photobiont: the cyanobacterium Nostoc lower surface: pale brown to yellow-brown, usually rugulose, glabrous to weakly pubescent Apothecia: immersed on lower surface at tips of lobes, orbicular, cup-shaped, sessile; margin: prominent with thalloid rim; disc: medium brown to dark brown; exciple: hyaline or light brown, 20-30 µm thick; epithecium: brown or brownish yellow; hypothecium: hyaline asci: c. 8-spored ascospores: subfusiform, 3-septate, 17-21 x 5-6 µm; wall thick, light brown Pycnidia: laminal, immersed, punctiform, 0.09-0.15 mm diam. conidia: rod-shaped, 4-5 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 an unknown brown pigment; medulla with triterpenes with: hopane-6α, 22-diol [zeorin] (major) and 15α-acetoxyhopane-22-ol [nephrin]. Habitat and ecology: on rocks and tree trunks in moist canyons at mid- to high elevations, most common in spruce-fir regions World distribution: Africa and Northern Hemisphere, where it occurs in subarctic, boreal and north temperate regions and extends south along the mountain chains Sonoran distribution: central and eastern Arizona.