TYPE. “Habitat in parietibus ligneis. Wahlenberg.” (Acharius 1803).

Description. Lichenized fungus.

Thallus crustose, distinct, granular-verrucose, ecorticate, grayish green to green. Photobiont Stichococcus alga. Ascomata stalked apothecia, 0.7-9.9 mm tall, stalk 0.05-0.08 mm diam., black, with a dense, yellowish green pruina in the upper part; capitulum broadly obovoid to lens-shaped; exciple well developed, with a dense, yellowish green pruina on the lower side. Asci cylindrical, not produced in chains, soon dissolving to produce a mass of spores (maezedium). Ascospores brownish, globose to ellipsoid, with a coarse and irregular ornamentation when mature, 4.5-9 × 3-4 µm diam.

Chemistry. The pruina contains vulpinic acid.

Substrate and Habitat. On trunks of deciduous trees in mixed hardwood forests.

Distribution. Cosmopolitan; in North Carolina found in the Blue Ridge ecoregion.

Literature

Acharius, E. (1803) Methodus qua Omnes Detectos Lichenes Secundum Organa Carpomorpha ad Genera, Species et Varietates Redigere atque Observationibus Illustrare Tentavit Erik Acharius. 394 pp. (original description as Calicium chlorellum).

Giavarini, G., O.W. Purvis & P.W. James (2009). Chaenotheca (Th. Fr.) Th. Fr. (1860). Pp. 297-303 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.