Collema subnigrescens Degel.

Syn.: Collema nigrescens (Huds.) DC. var. caesium (Clemente) Colmeiro, Collema nigrescens (Huds.) DC. var. subnigrescens (Degel.) Pišút, Collema subnigrescens Degel. var. caesium (Clemente) Degel., Parmelia nigrescens (Huds.) Ach. var. caesia Clemente, Synechoblastus nigrescens (Huds.) Trevis. f. caesium (Clemente) Hue
Lichenised.
Substrate: bark
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: a mild-temperate lichen found on the bark of more or less isolated broad-leaved trees; more thermophytic than the closely related C. nigrescens; apparently more frequent in the Southern and Western Alps.
Switzerland: Ticino; Unterwalden; France: Alpes-de-Haute-Provence; Alpes-Maritimes; Isère; Haute-Savoie; Vaucluse; Var; Italy: Friuli; Veneto; Piemonte;