Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: foliose to subcaespitose, very loosely adnate, up to 15 (-25) cm across, richly dichotomously or subdichotomously lobate lobes: 0.5-2 (-4) mm broad, strongly to moderately involute or flat or nearly so; apices: abundantly ciliate; cilia: up to 4 mm long, simple or more commonly branched upper surface: pale gray to gray; not sorediate or isidiate lower surface: black or brown or pale brown at the tips of the lobes, mostly erhizinate but some specimens with a few short, usually simple, black rhizines Apothecia: relatively infrequent, 4-6 mm diam. asci: clavate, 8-spored ascospores: ellipsoid or slightly reniform, 16-21 x 8-10 µm Pycnidia: common, 0.1-0.2 mm diam. conidia: bacilliform, straight, 5-7 (-8) x <1 µm Spot tests: upper cortex K+ yellow, C-, KC-, P+ yellow; medulla K+ yellow then turning deep red, C-, KC-, P+ yellow then orange Secondary metabolites: cortex with atranorin and chloroatranorin; medulla with salazinic acid (major), consalazinic acid (minor), galbinic and protocetraric acids (accessory) and a fatty acid. Substrate and ecology: on trees and shrubs, rarely on rock or soil World distribution: Mexico, Central and South America, southern Asia Sonoran distribution: Sierra Madre Occidental of Chihuahua.