Lichenographia Thomsoniana: 21 (1998).
Protolog: Thallus primarius persistens, squamulosus. Podetia 0.5-1.5 cm alta, simplicia vel parce racemosa, frequenter fertilia; superficie microsquamulosa, verruculosa vel sublaevia, areolato-corticata. Hymenia purpurea. Acidum thamnolicum et acidum didymicum continens.
Protolog type data: Mexico. Jalisco. Mpio. de Zapopan: Bosque La Primavera, 9 km from Periférico on the road Prolongación de Mariano Otero, alt. 1920 m, oak woods, on sandy erosion bank, 1 February 1996, Ahti 52711, Guzmán-Dávalos, Álvarez & Fanti (IBUG, holotype; ASU, B, DUKE, H, MEXU, NY, US, XAL, isotypes).
Type locality: Mexico, Jalisco, Municipio de Zapopan, Bosque La Primavera, 9 km from Periférico on the road Prolongación de Mariano Otero, oak woods, on sandy erosion bank, 1920 m, 1.2.1996, T. Ahti 52711, Guzmán-Dávalos, Álvarez & Fanti (IBUG - holotype; ASU, B, DUKE, H, MEXU, NY, US, XAL - isotypes).
Type locality coordinates: Data lacking.
Molecular barcode: Data lacking.
Thallus: Primary thallus persistent, consisting of elongate, incised, suberect to imbricate, green squamules, 2-5 mm long and 0.5-1 mm wide; underside arachnoid, white, turning orange-yellow at the very base, occasionally an orange streak extending higher up; rhizomorphs of hypothallus orange, often clearly visible in the soil, extending several cm outward from the squamules. Podetia when mature (fertile) 0.5-1.5 cm tall, rather stout, 0.5-2 mm thick, sometimes absent and apothecia sessile on squamules, simple to sparingly branched; ascyphose but sometimes with scyphoid axils. Surface of podetia greenish-gray (rarely browining), rather smooth, areolate-corticate or, more frequently, verruculose-granulose to heavily microsquamulose, esorediate; with few decorticate patches. Conidiomata on basal squamules, sometimes on the podetial microsquamules near tips of podetia; usually fairly large, 0.2-0.4 x 0.15-0.2 mm, ampullaceous, sessile to shortly stalked; containing red slime; conidia 8-10 x 1 µm. Hymenial discs very common, purple red, coalescent to form 2-5 mm wide compound discs, initially with tiny, often darker red, botryose ascogonial primordia (trichogynes visible) at tips of very young podetia; spores 11-12 x 5 µm, simple, oblong (Ahti & Guzmán-Dávalos 1998: 21).
Photobiont: Data lacking.
Chemistry: K+ yellow, P+ yellow; contains thamnolic acid, didymic acid as constant major secondary substances and inconstantly traces of usnic acid (rarely), decarboxythamnolic acid, condidymic acid and subdidymic acid (TLC) (Ahti & Guzmán-Dávalos 1998: 22).
Ecology: Data lacking.
Distribution Type: Mexico.
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