TYPE. UNITED STATES. South Carolina, Berkeley County, Santee Canal, on Taxodium distichum, H.W. Revenel 472 (FH, lectotype designated in Ertz (2009); CANB, CANL, FH, M, MICH, TENN, WIS, syntypes).
Description.Life form: lichenized fungus.
Thallus crustose, thin, up to 150 µm thick, pale grayish green to dark green, continuous; prothallus pale to dark brown, ~0.1-0.5 mm wide. Vegetative diaspores absent. Photobiont trentepohlioid alga. Ascomata lirellate, abundant, scattered, sessile, simple to 1-3-branched, straight to flexuose, 0.2-2.5 x 0.15-0.35(-0.4) mm; disk narrowly exposed, whitish pruinose; labia black or partially to entirely white pruinose. Exciple dark brown to slightly olivaceous, often thin to widely discontinuous below, 25-65 µm laterally; hypothecium pale to dark brown, 10-35 µm thick; hymenium hyaline, clear; paraphysoids branched, anastomosing, 1 µm thick, tips not swollen; epihymenium hyaline to pale brown, covered by layer or crystals 1-6 µm diam., persistent in K. Asci 8-spored, clavate to ellipsoid, 50-85 x 12-19 µm; ascospores hyaline, oblong, 3-7-septate, cells +/- equal in size, (13-)21.5-30.0 × (4-)5.0-5.5(-6.5) µm. Conidiomata not known.
Chemistry. Spot tests negative; no substances detected by TLC.
Substrate and Habitat. Corticolous on trees in forests and woodlands.
Distribution. Pantropical, eastern North America; in North Carolina found in the Coastal Plain ecoregion.
Literature
Ertz, D. (2009) Revision of the Corticolous Opegrapha Species from the Paleotropics. Bibliotheca Lichenologica No. 102. J. Cramer in der Gebrüder Borntraeger Verlagsbuchhandlung, Berlin and Stuttgart. 176 pp.
Perlmutter, G.B., S.C. Tucker, E. Rivas Plata, P. Clerc & R. Lücking (2015) Melaspilea demissa (Tuck.) Zahlbr. (lichenized Ascomycota) in eastern North America with a key to North American species of Melaspilea s. lat. The Lichenologist47(3): 167-182.
Tuckerman, E. (1866) Lichens of California, Oregon and the Rocky Mountains, so far as yet known. 35 pp (original description).