TYPE. “Habitat in American septentr. ad corticem arborum.” (Acharius 1814). North America. H. Muhlenberg s.n. (H-ACH 1070, lectotype designated by Brodo & Vitikainen 1984)

Description. Life form: lichenized fungus.

Thallus crustose, epiphloedal, pale yellow-gray to yellow-white, subcontinuous, smooth to thinly granular to verrucose. Vegetative diaspores absent. Photobiont chlorococcoid alga. Ascomata lecanorine apothecia, sessile, up to 0.5-0.8(-1.3) mm diam.; disk pale brownish, variously bluish pruinose, flat; thalline margin (amphithecium) pale, prominent. Epihymenium yellow-brown, dissolving in K; hymenium hyaline. Asci 8-spored; ascospores simple, hyaline, 11-13 × 6-8 µm.

Chemistry. Thallus K+ yellow, apothecial disk UV+ yellow or orange; atranorin, zeorin and lichexanthone (apothecial pruina).

Substrate and Habitat. Corticolous on trees.

Distribution. Eastern North America; in North Carolina found throughout.

Literature

Acharius, E. (1814) Synopsis Methodica Lichenum. Lund. 392 pp. (original description)

Brodo, I.M. & O. Vitikainen (1984) The typification of Lecanora subfusca (L.) Ach., its varieties, and some of its related taxa published before 1850. Mycotaxon 21: 281-298.

Harris, R.C. & D. Ladd. (2005) Preliminary Draft: Ozark Lichens, enumerating the lichens of the Ozark Highlands of Arkansas, Illinois, Kansas, Missouri, and Oklahoma. Published by the authors. 249 pp.

Morse, C. & D. Ladd. (2016) Lecanora inaurata, a new member of the L. subfusca group from central North America. The Lichenologist 48(5): 377-385.