LICHALP

Arthopyrenia arnoldii Zahlbr.

Lichenised. Poorly known taxon.

Substrate: bark

Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)

Note: a species with a thin, epiphloeodic, continuous, whitish thallus and minute, hemispherical to depressed ascomata (to 0.25 mm in diam) which are finally black and glossy, thin distinct branching interascal filaments, 4- to 8-spored asci (to 65 × 15 µm), 1-septate, ellipsoid to oblong ascospores with both cells of about equal size, surrounded by a perisporal sheath (14-18 × 5-8 µm), and bacillary pycnoconidia (to 4 µm long); based on a type from Italy where it was found on branches of Larix.