TYPE. “Habitat ad ligna & truncus arborum vetustos.” (Acharius 1816; H H-ACH 0495A, lectotype selected in Tibell 1994)
Description. Lichenized fungus.
Thallus crustose, thin, granular to verrucose, greenish to yellowish gray with a bluish tinge. Photobiont trebouxioid alga. Ascomata stalked capitulate maezedia, epruinose or with a whitish pruina on the lower side of capitulum. Stalk black to dark reddish brown, 0.5-1.3 mm tall. Capitulum narrowly obconical to lenticular, 0.2-0.55 mm diam.; mazaedium well developed, black; hypothecium blackish brown, with a convex upper surface. Asci narrowly clavate to cylindrical, dissolving early, with partly 2-seriate ascospores. Ascospores first simple, then (when released from asci) 1-septate, dark brown, broadly ellipsoid to ellipsoid, 9-12 x 4-7 µm, with a thick, minutely verrucose to areolate wall.
Chemistry. Thallus K-, C-, KC-, P-; maezedial stalk and exciple I+ deep blue; no lichen substances or with placodiolic and sometimes 4-O-methyhypoprotocetraric acids.
Substrate and Habitat. Lignicolous on decorticated conifer stumps and and trunks, as well as corticolous.
Distribution. Cosmopolitan, primarily cool-temperate to boreal-montane; in North Carolina found in the Blue Ridge ecoregion.
Acharius, E. (1816) Afhandling om de cryptogamiske Vexter, som komma under namn av Calicioidea, Andra Stycket. Acta Reg. Acad. Scient. Holm. 1816: 260-291 (original description).
Giavarini, V.J. & O.W. Purvis. (2009) Calicium Pers. (1794). Pp. 241-245 in Smith, C.W., A. Aptroot, B.J. Coppins, A. Fletcher, O.L. Gilbert, P.W. James & P.A. Wolseley (eds.). 2009. The Lichens of Great Britain and Ireland. The British Lichen Society, London.
Nimis P.L. (2022) ITALIC - The Information System on Italian Lichens. Version 7.0. University of Trieste, Dept. of Biology, (https://dryades.units.it/italic), accessed on 2022-09-15.
Tibell, L. (1987) Typification of names of infrageneric taxa described by Acharius and placed by him in Caliciales. Annales Botanici Fennici24: 257-280.