The genus name Fulgidea is derived from the Latin word fulgur, meaning "lightning", alluding to its preference for growing on burnt wood.

In Hypocenomyce, the exciple is colorless internally and green at the rim (K−, N+ violet), and is only partially conglutinated with hyphae separated by lecanoric acid crystals (C+ red).

Additionally, Hypocenomyce features a green epihymenium and pycnidium wall that react positively to violet staining with N and contains lecanoric acid, unlike Fulgidea which lacks amorphous substances.

Additionally, Pycnora has a strictly crustose thallus and a green epihymenium that turns violet with N and dissolves in K, with shorter pycnoconidia that are more or less spherical to shortly bacilliform.

Elixia, another genus, differs from Fulgidea as it forms a crustose or endoxylic thallus, with star-shaped to lirelloid apothecia, capitate paraphyses with a distinct pigment zone at the top of the apical cell, and lacks secondary compounds.