TYPE. ITALY. On bark of Fagus castanea (Massalongo 1852), A.B. Massalongo s.n. (F C0002591F, possible type)
Description. Lichenized fungus.
Thallus crustose, effuse, white to grayish or greenish olive; vegetative diaspores absent; prothallus brown to blackish. Photobiont trentepohlioid alga. Ascomata arthonioid apothecia, abundant, aggregated into concentric circles, irregular to substellate; disk flat, black. Ascomatal section 70–95 µm tall; epithecium dark red-brown, K+ green; hymenium 35–50 µm tall, hyaline or pale brown (K+ greenish); hypothecium 10–30 µm tall, dark red-brown, K+ dark green; paraphysoids 1–1.5 diam., numerous, the apices obscured by dense pigment. Asci pyriform, 8-spored; ascospores obovoid, hyaline to brown and warted when postmature, 7-septate to muriform, 15-25 x 7-10 µm. Pycnidia 60–80 µm diam., scarce, the wall red-brown, K+ green; conidia bacilliform, 4–6 × 1 µm.
Chemistry. No secondary compounds detected by TLC.
Substrate and Habitat. Corticolous on smooth-barked trees, usually near streams.
Distribution. Europe, North America (primarily eastern, but also in Pacific Northwest), Asia (South Korea, Vietnam); in North Carolina recorded from the coast and mountains – expected throughout.
Cannon, P., D. Ertz, A. Frisch, A. Aptroot, S. Chambers, B. Coppins, N. Sanderson, J. Simkin & P. Woseley. (2020). Arthoniales: Arthoniaceae. Revisions to the British and Irish Lichens1: 1-48.
Körber, G.W. (1861) Parerga lichenologica. Ergänzungen zum Systema lichenum Germaniae3: 193-288.
Joshi, S., B.G. Lee, D.K. Upreti & J.-S. Hur. (2018) New records of Arthoniaceae from Vietnam. Mycotaxon133: 103-112.
Massalongo, A.B. (1852) Ricerche sull'autonomia dei licheni crostosi. 221 pp. (original description as Arthonia ruana).