Thallus very thin, smooth, whitish. Photobiont absent. Ascomata stalked apothecia, 0.3-0.5 mm tall, black or with stalk greenish or gray-brown; capitulum lenticular to hemispherical, black, 0.2-0.3 mm diam.; stalk 0.04-0.08 mm diam., internally dull greenish or brownish, swelling in K. Epithecium thin, brownish; hypothecium hyaline to yellowish brown. Asci cylindrical, 8-spored, persistent; apex thickened, penetrated by a narrow canal. Ascospores uniseriate in ascus, brown, 6-7 × 2-2.5 µm, 1-septate, septum thin, much paler than spore wall; surface +/- smooth.
Chemistry. All brown or reddish pigmented parts K+ red, the reaction rapidly fading and the tissue turning greenish brown; no substances detected by TLC.
Substrate and Habitat. Lignicolous on wood of various trees, more rarely on conifers; associated with chlorococcoid alga, sometimes on Calicium glaucellum; often associated with other Chaenotheca species.
Distribution. Cosmopolitan in temperate, boreal and montane tropical regions; in North Carolina found in the Blue Ridge and Coastal Plain ecoregions, likely throughout.
Acharius, E. (1817) Afhandling om de cryptogamiske Vexter, som komma under namn av Calicioidea, Tredje Stycket. Acta Reg. Acad. Scient. Holm1817: 220-244.
Giavarini, V. & B.J. Coppins. (2009) Chaenothecopsis Vain. (1927). Pp. 303-307 in Smith, C.W., A. Aptroot, B.J. Coppins, A. Fletcher, O.L. Gilbert, P.W. James & P.A. Wolseley (eds.). The Lichens of Great Britain and Ireland. The British Lichen Society, London.
Nimis P.L. (2023). ITALIC - The Information System on Italian Lichens. Version 7.0. University of Trieste, Dept. of Biology, (https://dryades.units.it/italic), accessed on 2023-03-25.
Vainio, E.A. (1927) Lichenographia Fennica III. Acta Societatis pro Fauna et Flora Fennica 57(1): 1-138.