Mycoglaena myricae (Nyl.) R.C. Harris

Syn.: Arthopyrenia aeruginella (Nyl.) Arnold, Arthopyrenia myricae (Nyl.) Zahlbr., Verrucaria aeruginella (Nyl.) Nyl., Verrucaria myricae Nyl.
Non- or doubtfully lichenised.
Substrate: bark
Altitudinal distribution: subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)
Note: a probably non-lichenised species with an endosubstratic, inconspicuous thallus indicated by greyish to brownish patches, black, flattened perithecioid ascomata (to 0.5 mm in diam.), the ascomatal wall greenish-brown to greenish-black (N+ reddish to violet), persistent, branched and anastomosing interascal filaments, 8-spored fissitunicate asci lacking apical amyloid structures, and hyaline, fusiform, 3-septate ascospores with pointed ends (17-23 × 6-8 µm); usually on smooth bark of deciduous trees and shrubs (Myrica, Betula) but also on conifers; widespread in the Holarctic region but rarely collected, with a single record from the Eastern Alps (Austria).
Austria: Steiermark;