Thallus crustose, ecorticate, byssoid, pale greenish to whitish; prothallus distinct, white. Medulla white; photobiont Trentepohlia alga. Ascomata absent; asci developing in raised, whitish ascigerous areas, 8-spored; ascospores hyaline, muriform.
Chemistry. 2-O-methylperlatolic and confluentic acids.
Substrate and Habitat. Corticolous on trees, rarely saxicolous.
Distribution. Southeastern North America; in North Carolina in the Coastal Plain.
Notes. Based on the description and as reported by Thor (1991) and Lücking et al. (2011), this species belongs in the genus Cryptothecia, but distinct from C. striata by having 8-spored asci and a different chemistry. The type was last reported presumably in G, on loan (Thor 1991). Lücking et al. (2011) states that without examining the type, formal placement of A. montagnei in Crypothecia is postponed as recent material from the southeastern United States may represent a different species.
Literature
Harris, R.C. (1990) Some Florida Lichens. Published by the Author, Bronx, N.Y. 109 pp (as Arthonia montagnaei).
Lücking, R., F. Seavey, R. Common, S. Q. Beeching, O. Breuss, W. R. Buck, L. Crane, M. Hodges, B. P. Hodkinson, E. Lay, J. C. Lendemer, R. T. McMullin, J. A. Mercado-Díaz, M. P. Nelsen, E. Rivas Plata, W. Safranek, W. B. Sanders, H. P. Schaefer Jr., & J. Seavey. (2011) The lichens of Fakahatchee Strand Preserve State Park, Florida: Proceedings from the 18th Tuckerman Workshop. Bulletin of the Florida Museum of Natural History49(4): 127-186.
Thor, G. (1991) The placement of Chiodecton sanguineum (syn. Chiodecton rubrocinctum), and Cryptothecia striata sp. nov. The Bryologist94(3): 278-283.
Tuckerman, E. (1872) Genera Lichenum: an Arrangement of the North American Lichens. Amherst, Massachusetts (original description as Chiodecton montagnei).