Phaeocalicium tremulicola (Norrl. ex Nyl.) Tibell

Syn.: Stenocybe tremulicola Norrl. ex Nyl.
Non- or doubtfully lichenised.
Substrate: bark
Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: a non-lichenised species characterised by the less than 0.5 mm high, black, shining ascomata on olivaceous to greyish-brown stalks, a 2-layered exciple of an outer layer of large thick-walled cells and a thin inner layer of periclinally arranged hyphae, and 3-septate ascospores with only slightly uneven walls; only on twigs of Populus tremula; widespread in Northern Europe and also reported from the Eastern Alps (Austria).
Austria: Kärnten;