Type. UNITED STATES. “Ad corticem laevem in Carolina” (Nylander 1858), Tuckerman, E. s.n., s.d. (H H-NYL 1336, holotype)
Description. Lichenized fungus.
Thallus crustose, corticate, smooth, dark green, dark prothallus present; vegetative diaspores absent; photobiont Trentepohlia alga.
Ascomata perithecia, erumpent, mostly subglobose, black, 0.5-0.7 mm diam.; wall carbonized, black; hymenium clear, not inspersed, K/I+ orangish. Asci 8-spored, mostly in 1 row. Ascospores olive-green, ellipsoid, 4-celled, 32-42 x 13-17 μm.
Chemistry. UV-; secondary metabolites not detected.
Substrate and Habitat. On bark of hardwood trees in shaded forests.
Distribution. Eastern North America; in North Carolina throughout.
Notes. Pyrenula subelliptica is similar, distinguished by an inspersed hamathecium and round, subelliptic cell locules.
Harris, R.C. (1989) A sketch of the family Pyrenulaceae (Melanommatales) in eastern North America. Memoirs of the New York Botanical Garden 49: 74-107.
Nylander, W. (1858) Expositio Synoptica Pyrenocarpeorum: 1-88 (original description as Verrucaria punctella).