Acrocordia gemmata (Ach.) A.Massal.
Verrucaria gemmata Ach., Meth. Lich.: 120 (1803).
Thallus thin, ± filmy, whitish, smooth, continuous or cracked, sometimes limited by a dark line of prothallus. Perithecia black, erupting through surface of bark rounded to irregular, carbonaceous, smooth and shining or roughened, naked or invested with thin film of cortex, 0.2-0.9 mm diam., compound, one to several brownish apical pores, nearly superficial, leaving very shallow pits. Asci cylindrical 200-240 × 12-18 µm. Ascospores ellipsoid, 1-septate, 15-30 × 7-13 µm, upper cell larger, with a very complex dimple at the apex, 5-2 µm diam.
N: S: Throughout, on bark of introduced trees and shrubs in urban areas. Still very poorly collected.
Cosmopolitan