Hedwigia 52: 84 (1912).

Basionym: Porina pertusa var. areolata Ach., Syn. Meth. Lich. (Lund): 109 (1814).

Thallus: crustose, of deeply-cracked areolate to sub squamulose areoles, thick, 300-700 µm, varying from contiguous to dispersed. The areoles are similar, whether fertile or not, out to the margin of the thallus. Perithecia within the larger areoles, only the mouth showing with part of the involucrellum; the involucrellum thickened only near the mouth (subcompound in the sense of Swinscow), black or dark-brown, merging with the thallus tissue; exciple hyaline to pale-brown, blackening toward the mouth; spores 2 per ascus, dark-brown, muriform with many cells, ellipsoid or ovate, 20-50 x 15-25 µm (Thomson 1991: 354).

Photobiont: Data lacking.

Chemistry: No lichen substances.

Ecology: On acidic rocks, often near but not in the water. Western North American montane specimens range from 600 to 4000 meter.

Distribution type: Circumpolar temperate and boreal species, in North America ranging south and west from New England to Wisconsin, Colorado, Arizona, and California.

Taxonomy: Data lacking.

Note: Thomson gives the basionym as "Pyrenula areolata Ach., Synopsis Lich. 122. 1814" and "Type: The original type specimen of Pyrenula areolata in H-ACH was described by Vainio (1881), n.v. by me".

Distribution Database: Distributions

Picture Database: Tropical Lichens

Molecular Database: Genbank

Synonym Database: Index Fungorum

Synonym Database: Mycobank