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Data Set Maintenance: Data set standard item. Data set author(s): Triebel D. Data set reviewer(s): Triebel D. (98-01-01) and Scholz P. (02-05-16); revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: genus. Number of known taxa within this rank: 15. Placopyrenium. Verrucariaceae Zenker (1827); Verrucariales.

Taxonomic Literature: Breuss O. in Nimis P.L. & Poelt J., Stud. Geobot. 7, Suppl. 1: 1-269 [182] (1987); Breuss O. in: Nash T.H. III et al. (eds) Lichen Flora of the Greater Sonoran Desert Region vol. 1, 394-397; Ménard T. & Roux C., Mycotaxon 53: 129-159 (1995).

Biogeography: Checklist records: Austria, Germany, Italy, Sonoran Desert, and Sweden and Norway.

Lichen Photobionts: Primary photobiont present; chlorococcal. Secondary photobiont absent.

Thallus: Crustose or foliose, squamulose, placodioid, or areolate (primarily areolate). Upper Surface: Black, grey, or brown; special structures absent. Lower Surface: Attached by the whole lower surface or attached by holdfasts; special structures absent or present:; not pseudocyphellate; not cyphellate; not rhizinate or rhizinate; without thalloconidia thalloconidia; not cavernulate; not tomentose.

Medulla: Iodine reaction in Lugol's solution negative; not different with or without KOH pre-treatment (euamyloid).

Reproduction Strategy: Only known as sterile, asexually reproducing form or with sexual (and possible asexual) stages. Ascocarps: Perithecioid, orbicular, forming all across the thallus surface, not emerging. Wall: Not carbonized. Margin: Indistinct; external filaments absent. Exciple: Black, brown, white, or brownish yellow. Periphyses: Present. Hymenium: Iodine reaction: Lugol’s positive. Interascal Hyphae: Absent or present, scarcely branched, not or scarcely anastomosed. Hypothecium: White.

Asci: Tholus thickened, not amyloid; dehiscence verrucarial; exoascus not amyloid, not hemiamyloid.

Ascospores: c. 8 per ascus, ellipsoid or ovoid, (11.5)-13.5-15.2-17-(17.5) µm long, (4)-5-5.8-7-(7.5) µm wide, obtuse; septa absent or present; transversally septate, 0-1-3-transversally septate, formed by the proper spore wall; wall thin or thick, distinctly differentiated into primary and secondary wall, not thickened at the septum, hyaline, in Lugol's Solution negative, wall not ornamented.

Conidiomata: Absent resp. not observed or present; pycnidial; immersed, formed all accross the thallus surface.

Conidiogeneous Cells: Apical. Conidia: Bifusiform or bacilliform (to subcylindrical).

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