Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Thallus: fruticose, shrubby, often erect, up to 2.5 cm long branching: simple or sparingly branched, growing from a narrow holdfast branches: solid, flattened to weakly canaliculate surface: yellowish green, longitudinally grooved, often with slit-like perforations, without soredia or isidia pseudocyphellae: common, laminal, short linear, +depressed cortex: thin; chondroid strands: continuous, smooth Apothecia: laminal or subterminal, up to 2 mm in diam. disc: flat to convex, weakly pruinose, without white margin; margin: concolorous with the thallus, entire asci: elongate-clavate, 8-spored ascospores: hyaline, 1septate, narrowly ellipsoid, 10-13 x 3.2-3.5 µm Pycnidia: not observed Spot tests: cortex K-, C-, KC+ yellow, P-; medulla K-, C-, KC-, P+ deep yellow Secondary metabolites: cortex with usnic acid; medulla with psoromic acid (major). Substrate and ecology: on acidic rocks World distribution: restricted to southern Texas and northwestern Mexico Sonoran distribution: Chihuahua, Sonora, and Sinaloa.