Buellia disciformis (Fr.) Mudd f. microspora (Vain.) Zahlbr.

Syn.: Hafellia disciformis (Fr.) Marbach & H. Mayrhofer var. microspora (Vain.)
Lichenised.
Substrate: bark
Altitudinal range: from the submediterranean/colline belt (potential vegetation: mixed deciduous forests dominated by Quercus and Carpinus) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: morphology and ecology as in the typical form, but ascospores less than 20 µm long; based on a type from Northern Finland; distribution insufficiently known because not always distinguished.
Austria: Vorarlberg; Tirol; Salzburg; Kärnten; Steiermark; Oberösterreich; Niederösterreich (incl. Wien); Germany: Oberbayern; France: Alpes-de-Haute-Provence; Alpes-Maritimes; Vaucluse; Slovenia: Alpine and Pre-Alpine Slovenia;