Bryologist 85, 1: 79 (1982).

Protolog: Thallus robustus, laxe adnatus, corticola, cinereo-glaucescens, lobis rotundatis, 5-10 mm latis, laciniatis, margine ciliatis, ciliis sparsis, brevibus, 1-3 mm longis, superne planus, continuus, subtus albus, sparse rhizinosus, sorediis isidiisque destitutus, medulla alba, apothecia albo-maculata, substipitata, 3-10 mm diametro, disco perforato, sporae 16-20 x 8.5-11 µm, pycnidia numerosa, conidiis 16-23 µm; thallus K+ flavescens, medulla K+ rubra, P+ aurantiaca, atranorinum et acidum salazinicum continens.

Protolog type data: Mexico, State of Michoacán, Municipio of Arteaga, 38 km N of Playa Azul on road to Nueva Italia de Ruiz, in open oak woodland, elev. 600 m, 12 November 1977, Egan EL-10,983 (US-holotype; isotypes at ASU, DUKE, MIN, herb. R. S. Egan).

Type locality: Mexico, Michoacán, Municipio of Arteaga, 38 km N of Playa Azul on road to Nueva Italia de Ruiz, in open oak woodland, elev. 600 m, 12.11.1977, R. S. Egan EL-10,983 (US - holotype; ASU, DUKE, MIN, herb. R. S. Egan - isotypes).

Type locality coordinates: 18°21'0"N, 102°17'0?W; 18.35°, -102.283333°.

Molecular barcode: Data lacking.

Thallus: foliose, robust, broadly foliose to subfruticose, up to 10 cm across, loosely attached, corticolous, light mineral gray turning buff in the herbarium, lobes rounded and often becoming laciniate or elongate and ascending, lobes frequently growing in an overlapping pattern, upper surface plane to slightly rugose at the center of the thallus, soredia and isidia lacking, cilia sparse to occasional, short, black, 1-3 mm long, lower surface completely white except at the very center, rhizines sparse or rare, apothecia slightly stalked, large, white-maculate, disc perforate,spores 16-20 x 8.5-11 µm, pycnidia numerous, conidia long, 16-23 µm, cortex K+ yellow (atranorin), medulla K+ yellow to red (salazinic acid)" (Egan 1982: 79).

Photobiont: probably Trebouxia.

Chemistry: Cortex K+ yellow (atranorin), medulla K+ yellow to red (salazinic acid) (Egan 1982: 79).

Ecology: On bark.

Distribution: Endemic in Mexico.