[2] The genus was circumscribed in 2013 by lichenologists Ekaphan Kraichak, Robert Lücking, and H. Thorsten Lumbsch.

The genus is characterized by its greyish-white thallus covered by an epinecral layer, large apothecioid ascomata with exposed discs and thick, entire thalline margins, as well as a thin, reduced, uncarbonised proper exciple that lacks lateral paraphyses.

The genus features a non-inspersed hymenium, pale brown, non-amyloid ascospores, bacilliform conidia, and contains the norstictic acid chemosyndrome.

The genus name Xalocoa originates from the Catalan term xaloc, which signifies the sirocco, a warm wind that comes from the Sahara and affects Mediterranean regions.

The species epithet pays tribute to Xavier Llimona, a Catalan researcher known for his work on Mediterranean lichens and his contributions to the taxonomy of the genus Diploschistes.