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: a species resembling P. canellum in the grey, areolate, non-lobate thallus, but with smaller ascospores; a facultative parasite of Aspicilia aquatica on siliceous rocks along streams; widespread in Western and Northern Europe but rare, with records only from the Western Alps (France).
