Thallus crustose, thin, smooth, white; photobiont lacking. Ascomata perithecia, scattered, circular, subimmersed, 0.2-0.3 mm diam.; wall carbonized, entire or lacking below; hymenium colorless, K/I-; paraphyses 1.5-2 μm thick, with short cells, much branched and anastomosed. Asci clavate to cylindrical, inner surface of thickened tip with or without an indentation, 50-105 x 15-25 μm, 8-spored. Ascospores colorless, ellipsoid, muriform, usually constricted as septa, with thick perispore, 17-25 x 7-10 μm. Pycnidia black, subimmersed, 50-100 μm diam.; conidia colorless, rod-shaped, simple, 8-10 x 1-1.5 μm.
Chemistry. Spot tests not reported; Secondary metabolites not detected.
Substrate and Habitat. On bark of hardwood trees (e.g., oaks, hickories) in shaded forests.
Distribution. Europe and North America; in North Carolina found in Piedmont and Blue Ridge ecoregions.
Notes. Formerly known as Julella fallaciosa, this species was recently found to belong in the genus Arthopyrenia, which was also placed in the family Trypetheliaceae from molecular study (Thiyagaraja 2021). This species is rare in Europe.
Arnold, F. (1863) Die Lichenen des fränkischen Jura. Flora (Regensburg) 46: 601-604 (original description as Polyblastia fallaciosa Stitzenb. ex Arnold).
Coppins, B.J. (2009) Julella Fabre (1879). Pp. 450 in Smith, C.W., A. Aptroot, B.J. Coppins, A. Fletcher, O.L. Gilbert, P.W. & and P.A. Wolseley (ed.). The Lichens of Great Britain and Ireland. British Lichen Society, London.
Harris, R.C. (1973) The corticolous pyrenolichens of the Great Lakes region. Michigan Botanist12: 3-68 (as Polyblastiopsis fallaciosa).
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 (as Julella fallaciosa).
Thiyagaraja V., R. Lücking, D. Ertz, B.J. Coppins, D.N. Wanasinghe, S.C. Karunarathna, N. Suwannarach, C. To-Anun, R. Cheewangkoon, & K.D. Hyde. (2021) Sequencing of the type species of Arthopyrenia places Arthopyreniaceae as a synonym of Trypetheliaceae. Mycosphere12(1): 993–1011.