A crustose species with a thick, bright emerald green to sulphurous yellow-green granular thallus that may become brown when dry. The apothecia are borne or stalks and the cups often have a reddish brown pruina.
Calicium viride is widespread in central and eastern Scotland where it is found on wood and the dry, acid bark of oak and conifers in particular. BLS distribution map
Calicium viride is often found alongside Chaenotheca ferruginea, Chrysothrix candelaris, and Lecanactis abietina.
scottishlichens.co.uk 