Thallus: foliose, continuously forming rosettes or fragmentary, 3-8 (-15) cm wide, loosely adnate, lobate lobes: irregular, broad (3-8 mm wide), elongate, often thin; apices: usually subrotund, entire or frequently dissected marginally in teeth-like pattern, rarely ascending upper surface: usually medium to dark red-brown, occasionally with a bluish gray cast, shiny or somewhat pubescent, epruinose; isidia absent soredia: granular, marginal or laminal, in bluish gray, maculiform soralia; occasionally regeneration squamules present medulla: white photobiont: the cyanobacterium Nostoc lower surface: pale brown, naked or weakly pubescent or rarely tomentose, smooth to rugulose Apothecia: rare, immersed on lower surface at tips of lobes, orbicular, up to 8 mm diam., cup-shaped, sessile; margin: prominent with thalloid rim; disc: light brown; exciple: hyaline or light brown, 20-30 µm thick; epithecium: brown or brownish yellow; hypothecium: hyaline asci: 8-spored ascospores: subfusiform, 3-septate, 17-20 x 5-7 µm; wall: thick, light brown Pycnidia: rare, marginal, immersed, punctiform, 0.18-0.32 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 unknown brown pigment; medulla with hopane-6α, 22-diol [zeorin] (major), 15α-acetoxyhopane-22-ol [nephrin] and hopane-15α, 22-diol (trace or accessory) and an unknown. Habitat and ecology: on acidic rocks among mosses and tree trunks in moist canyons at mid- to high elevations, most common in spruce-fir regions World distribution: Northern Hemisphere where it occurs in boreal and north temperate regions and extends south along the inland mountain ranges Sonoran distribution: relatively common in central and SE Arizona and rarely in the northern part of Baja California. Notes: The soredia separate it from any other Sonoran Nephroma species. If the cyanobacterial photobiont of N. parile is not recognized, then this species might be mistaken for Melanelia subargenitifera.