Candelariella vitellina

Candelariella vitellina is a common and widespread green-yellow to orange-yellow crustose areolate lichen that grows on rock, wood, and bark, all over the world. It grows on non-calcareous rock, wood, and bark.

Taxonomy
The taxon Candelariella vitellina var. mendozae, proposed by Finnish lichenologist Veli Räsänen in 1941, was promoted to distinct species status, Placomaronea mendozae, in 2004.

Description
Candelariella vitellina often has tiny lobate in the shape of lion claws. The areoles may be flat or convex. Its sexual reproductive structures (apothecia) are a 0.35–1.0 mm-wide, darker yellow than the thallus, rimmed with thallus-like tissue (lecanorine), flat but becoming convex with age. The results of lichen spot tests are K+ reddish, KC−, and C−. It produces calycin, pulvinic acid, pulvinic dilactone and vulpinic acid as secondary metabolites.

Candelariella vitellina looks like a miniature version of C. rosulans. It can be distinguished by C. vitanela having a visible exciple (the rim around the apothecia disc), which C. rosulans does not have. It is usually much larger and thicker than the similar C. lutella.

Habitat and distribution
In California, it prefers growing on granite, but can also be found on wood (rarely on bark) and other kinds of rock.

Species interactions
It is a known host to the lichenicolous fungus species Carbonea vitellinaria.