TYPE. UNITED STATES. VERMONT, [Windham County] Brattleborough, C.C. Frost (DUKE 138860, isolectotype; FH 00213376, type; FH 0021377, type; F C0171675F, syntype; NY 1220750, isolectotype; WIS WIS-L-0088465, topotype)
Description. Lichenized fungus.
Thallus crustose, thin, continuous, pale gray; vegetative diaspores absent; photobiont Trentepohlia alga. Ascomata double-walled apothecia up to 0.6 mm diam. Disk becoming partly visible in older apothecia, grey-whitish pruinose; exciple not carbonized, apically pale, brownish toward base, occasionally shrunken, or incurved; epithecium hyaline to brownish; hymenium hyaline, clear, ~150 μm high. Paraphyses conglutinated, parallel, usually unbranched. Asci clavate, 4-8-spored. Ascospores hyaline, postmature brownish, tapered at one end and rounded at the other, 8-16-celled, 30–50 × 7–10 μm. Pycnidia not seen.
Chemistry. Spot tests all negative, secondary metabolites not detected.
Substrate and Habitat. On smooth bark of hardwood trees, in forests.
Distribution. North and South America, Oceania, Australia; in North Carolina found throughout.
Fink, B. (1935) The Lichen Flora of the United States. University of Michigan Press, Ann Arbor (description as Ocellularia subtilis).
Mangold, A., J.A. Elix & H.T. Lumbsch. (2009) Thelotremataceae, Flora of Australia57: 195–420.
Tuckerman, E. (1858) Supplement to an Enumeration of North American Lichenes. American Journal of Science and Arts25: 422-430 (original description).