Protolog type data: Argentina. Corrientes Province. Depto. Ituzaingó, Rincón Ombú Chico, L. I. Ferraro, S. Tressens, A. Schinini & M. Gonzales 687 25.iv.1975; CTES-holotype.

Type locality: Argentina, Corrientes Province, Depto. Ituzaingó, Rincón Ombú Chico, 25 April 1975, L. I. Ferraro, S. Tressens, A. Schinini & M. Gonzales 687 (CTES - holotype).

Type locality coordinates: Data lacking.

Molecular barcode: Data lacking.

Thallus: corticolous, loosely adnate, coriaceous, mineral grey, 4-10 cm in diam. Lobes rotund, 3-10 (-20) mm wide, margins broadly crenate, ciliate, cilia abundant, 0.5-2.5 mm long, rarely sparsely branched, lobes often becoming laciniate dissected, laciniae 1.0-2.0 mm wide, 0.5-8.0 mm long, + radiating. Upper surface plane, shiny, strongly effigurate white-maculate, becoming cracked with age, lacking soredia and isidia. Lower surface brown at the margins, black or brown-black at the centre; rhizines dimorphous, short rhizinate or papillate to the margins, short rhizines simple, dense, to 0.3 mm long, long rhizines coarse, sparse, formed in groups, more than 1.0-2.0 mm long. Apothecia common, stipitate, 4-10 mm diam., disc perforate, thalline exciple rugose, strongly white-maculate; spores 13-16 / 7-10 µm. Pycnidia common, conidia filiform, 10-14 / 1 µm (Ferraro & Elix 1993: 406).

Photobiont: Probably Trebouxia species.

Chemistry: Cortex K+ yellow; medulla K+ yellow turning red, C-, P+ orange; containing atranorin, chloroatranorin, salazinic acid (major), norlobaridone (major), consalazinic acid (minor/trace), loxodin (minor/trace) (Ferraro & Elix 1993: 406).

Ecology: Data lacking.

Distribution Type: Data lacking.

Note: Spelling also "P. cristobaliae".