Micarea prasina Fr.
Thallus composed of dense goniocysts, 12-18 µm diam., sometimes aggregated to form small granules, green-yellowish, more or less dark green, grey-greenish. Apothecia convex to subglobose, sometimes tuberculate, 0.2-0.4 mm diam., whitish, greyish, pale brown-greyish, blackish, exciple inconspicuous, often absent. Ascii utriform, 8-spored, 5-60 x 20-25 µm according to our measures. Ascospores colourless, ovoid to oblong, simple, 1-3-septate, 8-12 x 3-4 µm according to literature, 10-13 (15) x 4-5,5 µm according to our measures. Photobiont: micareoid. Thallus and apothecia: C-, K-, KC-, Pd-. On stumps, tree trunks in old woodlands, seldom on ground or rocks. N.B. It seems wise to consider Micarea prasina sensu lato since there are at least two other taxa very difficult to distinguish unless a chemical analysis is performed: Micarea micrococca that would be the most common and Micarea subviridescens which shows maritime trends. These two latter taxa sometimes are considered as chemotypes of Micarea prasina or separate species.