Tholurna is a genus of lichenized fungi in the family Caliciaceae.

[2] The genus is monotypic, containing the single species Tholurna dissimilis.

This species was first described by Johannes Musaeus Norman as Podocratera dissimilis in 1861; he circumscribed the new genus Tholurna the same year to contain the species.

It is found in Scandinavia and western North America.

This Caliciales-related article is a stub.