Brianaria was introduced in 2014 to accommodate the long-recognised "
Micarea sylvicola group", whose species proved—by DNA analyses and shared anatomical traits—to fall outside
Micarea in the strict sense. The authors recombined four former
Micarea species as
Brianaria. The genus name honours
Brian John Coppins for his work on
crustose lichens. In
phylogenetic studies
Brianaria forms a single, well-supported
lineage within the family
Psoraceae and is probably the
sister group to
Psora and
Protoblastenia, rather than part of the
Ectolechiaceae where
Micarea sits. The separation of the genera rests on clear diagnostic .
Brianaria has a green-algal partner () that is not the type typical of
Micarea; its tiny, convex fruiting discs (
apothecia) lack a distinct rim (no ); the spore sacs (
asci) are of the
Psora-type with a broad, dark "tube" that widens towards the tip; the accessory filaments in the
hymenium () occur in two forms (dimorphic); the
sexual spores are 0–1-septate; and the
asexual reproductive structures (
pycnidia) are sunk in the thallus and produce short, rod-shaped
conidia. Taken together, these features set
Brianaria apart from
Micarea in the strict sense, from
Psora (which is
squamulose in form and chemically different), and from
Protoblastenia (which has
anthraquinone pigments and a developed rim). Nomenclaturally, the
type species traces back to
Lecidea sylvicola, validated by
Gustav Wilhelm Körber in 1855 (after an invalid mention by
Julius von Flotow in 1829), later placed in
Micarea, and finally transferred to
Brianaria when the genus was erected. ==Description==