About Calicium viride Pers.
Calicium viride Pers. has a greenish-yellow, granular-textured thallus that grows as a crust on its substrate. Small black stalks, measuring 1.5–2.5 mm long and roughly 0.1–0.15 mm thick, support its spore-bearing structures called apothecia. Each stalk ends in a capitulum, which is a spherical apothecium. Overall, the total height of the apothecium is approximately 9 to 16 times greater than the width of its central stalk. The capitula are black, with a brownish underside. Its ascospores are brown and elliptical in shape, with a single internal septum that splits the spore into two cells. The spores measure 12–14 μm by 6–7 μm. This lichen contains the secondary lichen products rhizocarpic acid and epanorin. In terms of habitat and distribution, Calicium viride is most commonly found growing on the bark and wood of conifer trees in montane forests, though it sometimes grows on deciduous trees. It prefers bark that is weakly acidic to neutral. Chaenotheca trichialis is a frequent lichen associate that grows alongside it.
