TYPE. UNITED STATES. FLORIDA, [Duval County], Ft. George Island, on Ilex cassine, 1886, W.W. Calkins 118 (NY 01217551, isotype?; F possible type).
Description. Lichenized fungus.
Thallus crustose, ecorticate, thin, continuous, whitish or greenish-white, effuse; vegetative diaspores absent; prothallus indistinct; photobiont chloroccoid alga. Ascomata arthonioid, black, often appearing pruinose, punctiform to irregular, often aggregated, convex, 0.1 x 0.2 mm. Exiple brownish, indistinct; epithecium brownish; hymenium hyaline, not inspersed, gel I+ orange; hypothecium hyaline. Asci arthonioid (subglobose), 8-spored; ascospores hyaline, 5-9-septate, 10-22 x 9-10 μm; cells equal-sized (not macrocephalic). Pycnidia not reported.
Chemistry. Spot tests negative; secondary compounds not detected by TLC.
Substrate and Habitat. Corticolous on smooth barked trees in forests.
Distribution. Southeastern North America, where it appears endemic to the coastal plain; in North Carolina found in Coastal Plain to the Fall Line bordering the Piedmont ecoregion.
Eckfeldt, J.W. (1889) Some new North American lichens. Bulletin of the Torrey Botanical Club 16(4): 104-106 (original description).
Fink, B. (1935) The Lichen Flora of the United States. University of Michigan Press, Ann Arbor (description as Arthothelium albovirescens).
Lendemer, J.C. & N. Noell, (2018) Delmarva Lichens: An illustrated manual. Memoirs of the Torrey Botanical Society 28: 1-386.