TYPE. CANADA. Nova Scotia, Cape Breton Island, Victoria Co., Franey Mt. trail near Ingonish, on trunk of Fagus, 06.VIII.1952, I. Mackenzie Lamb 6985 (CANL 11613, holotype)
Description.Life form: lichenized fungus.
[modified from Dibben 1980] Thallus crustose, gray or greenish gray, epiphloedal, thin to moderately thick; margin entire and infrequently zoned. Surface smooth and verrucose, shiny, rimose to rimose-areolate; areoles (0.2-)0.8(-2.5) mm diam. Vegetative diaspores absent. Fertile warts conical or flat-topped, dispersed to crowded, solitary or 2-3(-4) fused, or as deformed aggregations (0.4-)1.4(-2.8) mm diam. Ostioles 1 or 2-7(-10) per fertile wart, hyaline, thallus colored or dark beneath, level or sunken, (0.05-)0.3(-0.8) mm diam, and grouped or isolated in prominent, well-dispersed, wart depressions (3-5 per verruca) with yellow or white borders. Ascomata pertusarioid apothecia, (1-)2-5(-7) per wart, (0.31-)0.53(-0.90) mm diam., hymenium hyaline to yellow-brown (+/- pink). Hypothecium hyaline or pale; epithecium hyaline or dark. Asci clavate or cylindrical, (200-)320(-490) x (35-)60(-80) μm; ascospores (1-)2(-4) per ascus, uniseriate, longitudinal or oblique, fusiform, often filled with oil droplets when immature, (90-)155(-235) x (30-)50(-80) μm. Outer spore wall (1-)4(-8) μm thick; inner spore wall (2-)12(-22) μm thick, strongly convoluted on the inner surface, radially zoned and channelled; end wall (8-)25(-58) μm thick. Conidiomata not reported.
Chemistry. Spores K+ violet; cortex UV- or + weak orange-pink, K- or + weak yellow, KC- or + weak yellow, C-, PD-; medulla K+ yellow, KC-, C-, PD+ yellow to orange. 2,7-dichlorolichexanthone, stictic acid, and constictic acid.
Substrate and habitat. Corticolous on hardwood trees, rarely on conifers.
Distribution. Central and eastern North America; in North Carolina found throughout.
Dibben, M.J. (1980) The Chemosystematics of the Lichen Genus Pertusaria in North America North of Mexico. Publications in Biology and Geology No. 5, Milwaukee Public Museum Press, Milwaukee. 162 pp.
Lamb, I.M. (1954) Lichens of Breton Island, Nova Scotia. Annual Report of the National Museum of Canada132: 239-313 (original description as Melanaria macounii).