Saccardo (1883) erected the subgenus Brunaudia for the single species Triblidium phormigenum, dedicating the new subgeneric name to the French mycologist Paul Brunaud. Lindau (1879) listed Brunaudia with a question mark amongst the synonyms of Tryblidiella (invalidly published. Art. 34). Later, Kuntze (1898) raised subgenus Brunaudia [as "Bruneaudia"] to the rank of the genus, synonymized it with Triblidium Dufour (non Rebent.), and transferred in it a group of species, also including taxa from Triblidiella Sacc. Rehm (1904) considered Brunaudia to be a typical hysteriaceous taxon: "... welche zu den echten Hysteriaceen zu rechnen ist". The generic name Brunaudia has not been mentioned in most mycological literature (e.g. in Oudemans 1924, Clements & Shear 1931), but is cited in Fan- et al. (1979) with a note that it was: "... Published as a substitute name for Tryblidium Dufour 1828 (nom. inval.). FUNGI [caet.]-helotiales (109)", and also in editions of the Dictionary of the Fungi and the Outline as a possible synonym of Rhytidhysteron. However, we can see no nomenclatural obstacle to its use, and it clearly has nothing to do with the Patellariaceae.

The thin-walled asci are without any apical thickenings, indicating that they are presumably unitunicate. The subcuticular and later erumpent habit of the apothecioid ascomata, and the absence of a developed exciple at the base of the type species suggest relationships with the members of the Rhytismataceae Chevall. However, this genus has no stromatic layer covering the hymenium and does not rupture either by a single slit (e.g. as in Lophodermium Chevall.) or by several radial splits (e.g. as in Coccomyces De Not. or Propolis Fr.). The mode of rupturing is, however, similar to that seen in Rhabdocline pseudotsugae Sydow, which opens by the overlying clypeus folding back in one piece. On the other hand, the genus resembles erumpent and marginate members of the Dermateaceae Fr. (e.g. Laetinaevia Nannf.), but differs in lacking a fleshy exciple of isodiametric and brown-walled cells, and the absence of spore discharge apparatus in the ascus apex.

Nevertheless, at the moment we consider that the genus Brunaudia is best placed tentatively in the Rhytismatales, but as incertae sedis rather than in a particular family.

The type collection consists of four specimens with numerous ascomata. However, in all sections or squash mounts of ascomata examined we failed to observe asci, and only discovered a few scattered ascospores. Therefore, the above description of the asci and ascospores is largely based on the protologue and W. Phillips drawings and brief notes attached to the type collection.

The fungus starts developing directly below the host cuticle and is observed as a brownish structure in the uppermost 1-2 layers of epidermis cells. As development progresses, the ascomatal margin pushes the cuticle back and breaks it on first one side, but soon along the whole perimeter of the ascomata. Consequently, the clypeus is thrown off, and the margin then extends above the surface of the substrate.

In external appearance this fungus resemble Lophodermium or Hypoderma, but is distinguished from both these genera by at least the absence of defined longitudinal split in the ascomata and the stromatic developed tissue above the hymenium.

Studies of fresh collections are needed to certainly extend our knowledge of this fungus.