TYPE. UNITED STATES. Louisiana, M.E. Hale s.n. (FH-TUCK, lectotype designated by Hale 1981).
Description.Life form: lichenized fungus.
Thallus crustose, epiphloedal, whitish mineral gray, 3-10 cm wide, ~1 mm thick, dull, fissuring and sometimes bulging from the substrate; vegetative diaspores absent. Cortex lacking; medulla compact, cellular, 150-200 μm with algae between vertical blocks; photobiont trentepohlioid alga in a well-developed layer. Ascomata pore-like apothecia, abundant, ~0.4 mm diam., irregular to angular, solitary or fused and clustered, often forming stroma-like structures, immersed; inner exciple clearly developed, free from broad thalline margin; pore round, irregular to angular, 0.35 mm diam; disk visible from above, grayish-pruinose. Exciple free apically, hyaline to yellowish; epihymenium hyaline with grayish to brownish granules; hymenium ~120 μm high, moderately conglutinated; paraphyses straight to slightly bent, anastomosed, slightly branched towards the margins, with slightly thickened tips. Asci 8-spored; ascospores brown, submuriform, 7-17 x 5-9 μm, I-.
Substrate and Habitat. Corticolous and hardwood trees.
Distribution. Pantropical and subtropical; in North Carolina found in Coastal Plain and Piedmont ecoregions.
Hale, M.E. Jr. (1981) A revision of the lichen family Thelotremataceae in Sri Lanka. Bulletin of the British Museum (Natural History), Botany Series8: 227-332 (description as Myriotrema glaucescens).
Mangold, A., J.A. Elix & H.T. Lumbsch. (2009) Thelotremataceae, Flora Australia57: 195–420.
Nylander, W. (1863) Prodromus Florae Novo-Granatensis ou enumeration des plantes de la Nouvelle-Grenade. Lichenes. Annales des Sciences Naturelles Botanique4(19): 286-382 (original description as Thelotrema glaucescens).