Diplotomma alboatrum (Hoffm.) Flot. forme corticole.
Diplotoma alboatrum éco alboatrum
Differs from other forms by its habitat: bark of deciduous trees. Thallus thin, whitish to greyish, pale ochre. Apothecia numerous, erumpent, disc markedly convex, black. Asci 8-spored, 60-65 x 20-25 µm according to our measures. Ascospores broadly ellipsoid, dark brown, 3-septate-like at first, then muriform at maturity, 15-19 x (7) 8-10 µm according to our measures. C-, K-, KC-, Pd-. Rather rare form occurring on the bark of deciduous trees.