Type. UNITED STATES. ARKANSAS, Dardanelle, 1853, Michener s. n. (FH, holotype; M—isotype).
Description. Lichenized fungus. Thallus crustose, endophloedal, smooth, yellow-green, no prothallus; vegetative diaspores absent; in section heteromerous, including cortex and medulla, most prominent in raised warts (pseudostromata); photobiont Trentepohlia.
Ascomata perithecia, clustered in low to raised pseudostromata, appearing as aggregations of black dots (ostioles); wall carbonized, black; hamathecium colorless, clear; paraphysoids thin, anastomosing. Asci clavate with a distinct foot, 8-spored. Ascospores colorless, 8-12-celled, locules diamond-shaped, 38-52 x 7-10 μm, I- or weakly I+ violet-blue. Pycnidia occasional, scattered; conidia not described.
Chemistry. Spot tests: UV-, K-; secondary metabolites not detected.
Substrate and Habitat. On smooth bark trees in forests.
Distribution. Eastern North America and eastern Asia (Japan, Thailand); in North Carolina throughout.
Notes.Virodothelium virens is the northernmost member of an otherwise mostly tropical lichen family. It was recently split from the genus Trypethelium into a new genus by molecular and morphological data in an overall revision of the family Trypetheliaceae (Aptroot & Lücking 20116, Lücking et al. 2016).
Aptroot, A. & R. Lücking.( 2016) A revisionary synopsis of the Trypetheliaceae (Ascomycota: Trypetheliales). The Lichenologist48(6): 763-982.
Brodo, I.M., S. Duran Sharnoff & S. Sharnoff. (2001) Lichens of North America. Yale University Press, New Haven & London. 795 pp (description as Trypethelium virens).
Darlington, W. (1853) Flora Cestrica: an herborizing companion for the young botanists of Chester County, State of Pennsylvania (3rd ed.). Lindsay & Blakiston, Philadelphia (original description as Trypethelium virens).
Lücking, R., M.P Nelsen, A. Aptroot, R.B. Klee, P.A. Bawingan, M.N. Benatti, N.Q. Binh, F. Bungartz, M.E.S Cáceres, L.S. Canêz, J.-L. Chaves, D. Ertz, R.E. Esquivel, L.I. Ferraro, A. Grijalva, C. Gueidan, J.E. Hernández, A. Knight, H.T. Lumbsch, M.P. Marcelli, J.A. Mercado-Diaz, B. Moncada, E.A. Morales, K. Naksuwankul, T. Orozco, S. Parnmen, E. Rivas Plata, N. Salazar-Allen, A.A. Spielmann & N. Ventura. (2016) A phylogenetic framework for reassessing generic concepts and species delimitation in the lichenized family Trypetheliaceae (Ascomycota: Dothideomycetes). The Lichenologist48(6): 739-762.