TYPE. UNITED STATES. Tennessee, Great Smoky Mountains, above National Park Office, on boulder in deciduous forest, about 700 m, on granitic rock, 1939, G. Degelius s.n. (Degelius 1941).
Description.Life form: lichenized fungus.
[Modified from Degelius (1941)] Thallus in the specimens seen up to at least 2 x 4 cm, uniform in thickness, ~0.2(-0.4) mm, pale sordid grayish green. Circumference not definite, but dissolved into 0.5 mm diam., +/- scattered, thin but uneven areoles, partly with free and crenulate edges, squamule-like, K-, I-. Surface overall uneven with low protuberances between irregularly arranged fissures. No hypothallus observed. Upper cortex 20-25 µm, hyaline with yellow-olive surface, partly filled with air, cellular, cells 3.5-5(-7) µm, often angular, very thin-walled. Photobiont chlorococcoid alga, cells 10-20 µm, bright yellow-green, thin-walled, in a well-defined layer 50-80 µm thick. Medulla hyaline, composed of loose hyphae, cells 4-7.5 µm thick, thin-walled, partly filled with oil, especially below apothecia.
Ascomata aspiciloid apothecia; disk 0.3-0.5 mm diam., usually regular; margin prominent above thallus surface, wall-like. In section 150-200 µm deep. Hypothecium hyaline, ~35 µm, distinctly cellular, cells angular, 1.7-2.5(-3) µm. Hymenium 110-135 µm high, I+ greenish yellow; epihyemenium 30-35 µm, olive to greenish. Paraphyses dense, 1.7 µm; tips expanded, 4-5 µm thick, moniliform, cells subglobular, distinct in K, bright green in HCl. Asci 85-100 x 25 µm, broadly clavate, 8-spored. Ascospores 15-17 x 10-12 µm, broadly ellipsoid, rare. Pycnidia 85-100 µm diam., wall pale; conidia 12-14 x 0.8 µm, straight.
Substrate and Habitat. Saxicolous on granitic rock.
Distribution. Eastern North America; in North Carolina reported from the Blue Ridge ecoregion.
Literature
Degelius, G.N. (1941) Contributions to the Lichen flora of North America I. The lichen flora of the Great Smoky Mountains. Arkiv för Botanik 30A, Nr. 3: 1-80.