TYPE. UNITED STATES. TENNESSEE, Great Smoky Mts., near Alum Cave, alt. 1515 m, on moist rock, 13.IX.1939, G. Degelius s.n. (UPS, holotype; CANL, MIN, S, US, isotypes).
Description. Lichenized, tripartite fungus.
Thallus fruticose. Primary thallus rudimentary and disappearing, composed of granular or squamule-like, corticate structures (phyllocladia), rarely seen. Pseudopodetia growing from primary thallus, whitish, up to 5 cm tall, ligneous, erect, base blackish, main axes somewhat distinct; branching loose, forming slightly prostrate tufts. Phyllocladia abundant, evenly distributed but not covering pseudopodetia, cylindrical, branched, up to 2 mm long, 0.1 mm diam. Photobiont trebouxioid alga; cyanobiont Stigonema in cephalodia; cephalodia common, olive brown to bluish, globose, 0.5-2 mm, clustered on upper pseudopodetial branches. Ascomata biatorine apothecia, infrequent, terminal; disk flat to convex, brownish black to black. Epithecium reddish brown; hymenium hyaline, I- or + bluish; paraphyses simple, tips capitate. Asci abundant, 45-50 x 14-16 μm; tholus I+ dark blue, otherwise I+ light blue, 6-8-spored. Ascospores hyaline, hyaline, 3-6-septate, 28-34 x 3-4 μm, one end tapered and other rounded, straight or slightly curved.
Chemistry. K+ dingy yellow or K-, KC+ pink or KC-, C-, PD-; atronorin, lobaric acid.
Substrate and Habitat. On exposed or somewhat shaded non-calcareous rock outcrops, talus slopes and cliff faces.
Distribution. Asia (Japan), Europe (Sweden), eastern North America; in North Carolina in the Blue Ridge ecoregion.
Literature
Brodo, I.M., S. Duran Sharnoff & S. Sharnoff. (2001) Lichens of North America. Yale University Press, New Haven & London. 795 pp.
Carlin, G. (1998) Stereocaulon tennesseense new to Sweden. Graphis Scripta9(2): 33-34.
Dey, J.P. (1978) Fruticose and foliose lichens of the high-mountain areas of the southern Appalachians. The Bryologist81(1): 1-93.
Lamb, I.M. (1977) A conspectus of the lichen genus Stereocaulon (Schreb.) Hoffm. Journal of the Hattori Botanical Laboratory43: 191-355.