Caeruleum heppii (Hepp ex Arnold) K. Knudsen & Arcadia

Syn.: Acarospora heppii Hepp ex Arnold, Myriospora heppii Nägeli ex Hepp nom. inval.
Lichenised.
Substrate: calciferous rocks, intermediate rocks (such as calciferous schists)
Altitudinal range: from the mesomediterranean belt (potential vegetation: evergreen broad-leaved forests dominated by Quercus ilex) to the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)
Note: an easily overlooked early coloniser of small calcareous pebbles in dry grasslands, which also occurs on concrete and mortar in small settlements and on walls of calciferous sandstone; widespread in the Alps below the subalpine belt, but only locally common.
Austria: Vorarlberg; Tirol; Salzburg; Kärnten; Steiermark; Oberösterreich; Niederösterreich (incl. Wien); Germany: Oberbayern; Schwaben; Switzerland: Luzern; Schwyz; Unterwalden; Valais; France: Haute-Savoie; Italy: Veneto; Trentino Alto Adige; Lombardia;