TYPE. “Hab. ad Aceris platanoides aliarumque arborum cortices.” (Schrader 1797); Schrader s.n. (GOET, lectotype).

Description. Non-lichenized, allied fungus.

Thallus crustose, endophloeodal, whitish; prothallus absent. Photobiont absent. Ascomata arthonioid apothecia (irregular – lirelliform, +/- branched), immersed-semisessile (base not constricted), erumpent; length 0.1-0.8 mm; width ~0.1 mm; thickness 30-60 μm; disk black, epruinose, +/- convex; exciple olivaceous brown, 5-10 μm; hyphae olivaceous brown, smooth, ~2 μm thick. Epithecium olivaceous brown, 5-10 μm; paraphysoids olivaceous brown, smooth, densely arranged, orientated in all directions, 2.0-2.5 μm; tips free, with distinct apical caps, gel brown (also in KOH), and granular. Hymenium hyaline, 30-40 μm; paraphysoids hyaline, smooth, c. 1 μm, richly branched; hymenial gel hyaline, granular, with granules. Hypothecium hyaline, up to 10 μm; hyphae hyaline, smooth, c. 1 μm. Asci broadly ovoid, without distinct stipe; ascus wall not laterally thickened; tholus without horizontal layers, 20-30 x 14-20 μm. Ascospores broadly ovoid, straight, persistently hyaline and smooth, with epispore, often incised at the septum, 1-septate, 10-15 x 3-5 μm. Pycnidia black, immersed, up to 0.1 mm; wall olivaceous brown; conidia bacilliform, straight, 3-5 x 0.5-1.0 μm.

Chemistry. Thallus I-, K/I+ blue; hymenial gel I+ blue, K/I+ blue; no lichen substances detected by TLC.

Substrate and Habitat. Corticolous on trees, where it is a pioneer, sun-loving species on young trunks and twigs of hardwoods.

Distribution. Temperate Europe, North America; in North Carolina the species is represented by two historical records from two counties in the Piedmont ecoregion [Forsyth: L.D. v. Schweinitz s.n., s.d. (PH PH00078486) and Gaston: H.A. Greene s.n., 1886 (MICH 74811), respectively].

Notes. Naevia dispersa was selected as the type species of the genus resurrected by Thiyagaraja et al. (2020).

Literature

Fink, B. (1935) The Lichen Flora of the United States. University of Michigan Press, Ann Arbor. 426 pp (as Arthonia dispersa).

Schrader, H.A. (1797) Systematische Sammlung cryptogamischer Gewächse. Zweyte Lieferung. Annalen der Botanik (Usteri) 22: 75-87 (original description as Opegrapha dispersa).

Sundin, R. & A. Tehler. (1998) Phylogenetic studies of the genus Arthonia. Lichenologist 30(4-5): 381-413 (description as Arthonia dispersa).

Thiyagaraja, V., Lücking, R., Ertz, D. et al. (2020) Evolution of non-lichenized, saprotrophic species of Arthonia (Ascomycota, Arthoniales) and resurrection of Naevia, with notes on Mycoporum. Fungal Diversity 102: 205–224