Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Thallus: crustose, effuse, rimose to areolate, sometimes bullate, up to 0.4 mm thick upper surface: creamy white to greenish, smooth to verrulose upper cortex: up to 30 µm thick, composed of interwoven hyphae with hyaline tips medulla: white, cretaceous prothallus: often present, thin, smooth, black Ascomata: perithecioid, punctiform, up to 0.5 mm diam., immersed or subimmersed, rounded, oval, or elongate, scattered or often united and lirellate, aggregated into stroma-like structures without a constricted base, surrounded by a thin thalline margin or undifferentiated; disc: plane, black, with whitish pruina; proper exciple: up to 10 µm thick, pale brown; hypothecium: pale brown, fusing with the medulla; hymenium: hyaline, 300-350 µm thick, I+ reddish, K/I+ pale blue; subhymenium: pale brown, up to 50 µm thick asci: 100-120 x 20-23µm, 8-spored ascospores: ellipsoid-fusiform, with lower end tapering to narrow apex, hyaline when young, brown at maturity, 30-42 (-45) x -8 µm, (3-) 5-7 septate, constricted at one (rarely more) septum, with thick gelatinous sheath Pycnidia: laminal, subglobose, up to 0.35 mm tall and 0.25 mm wide; walls: colorless or reddish brown at upper part conidia: filiform, curved, 14-18 x 1 µm Spot tests: thallus and medulla K- or K+ yellowish, C-, KC-, P+ yellow (orange) Secondary metabolites: psoromic acid (major) and 2'-O-demethylpsoromic acid (minor). Substrate and ecology: on bark in the Magdalena region of the Sonoran Desert World and Sonoran distribution: only known from two nearly coastal localities in Baja California Sur. Notes: The submuriform spores are unique among the group.