Description. Thallus effuse, squamiform/areolate; squamules/areoles 0.1-0.5 mm diam, adnate to ascending, isodiametric to elongated, scattered when young, later often contiguous or imbricate, crenulate to incised, flat to weakly convex, dull green. Upper surface smooth; margin usually faintly pubescent. Prothallus indistinct or partially developed, white to reddish-brown. Vegetative diaspores isidia (marginal proliferations in Lendemer & Noell 2018), common, attached to squamule margins, thin to medium thick, long, simple or rarely branched. Upper cortex 15-25 μm thick, lacking crystals; medulla white; photobiont chlorococcoid alga. Ascomata biatorine apothecia, common, up to 1.5 mm diam., rounded becoming irregular, solitary; disk flat to moderately convex, pale to medium brown; margin indistinct, smooth to finely pubescent, usually paler than disk. Exciple pale brown to hyaline; hypothecium pale brown to hyaline, not inspersed; hypothecium pale brown to hyaline; epihymenium hyaline. Asci 8-spored; ascospores hyaline, narrowly ellipsoid or shortly bacilliform, simple, 6.5 – 14.5 x 2 – 2.5 μm. Conidiomata pycnidia; conidia bacilliform, 5-10 x ~1 μm.
Chemistry. UV-, K-, KC-, C-, PD-; no lichen substances or small amounts of argopsin or atranorin detected by TLC.
Substrate and habitat. Corticolous on conifers and hardwoods in mesic and humid forests.
Distribution. Neotropical, north to eastern North America; in North Carolina found in Blue Ridge and Coastal Plain ecoregions, expected throughout.
Literature
Kistenich, S., M. Bendiksby, S. Ekman, M.E.S Cáceres, J.E. Hernández & E. Timdal (2019) Towards an integrative taxonomy of Phyllopsora (Ramalinaceae). The Lichenologist51(4): 323-392.
Lendemer, J.C. & N. Noell. (2018) Delmarva Lichens: An illustrated manual. Memoirs of the Torrey Botanical Society28: 1-386.
Timdal, E. & H. Krog (2001) Further studies on African species of the lichen genus Phyllopsora (Lecanorales). Mycotaxon77: 57-89.