[9] This taxonomic proposal was rejected by Robert Lücking in a critical 2019 review of the temporal method for the classification of lichen-forming fungi, using this specific example to highlight several drawbacks of this approach.

It varies in colour from grey-white to dark grey or yellowish and can have a smooth to warty (verrucose) surface, often covered with a powdery coating (pruinose).

[11] The ascomata (fruiting bodies) start off resembling perithecia (flask-shaped structures) and later become urn-shaped (urceolate) and immersed in the thallus.

It consists of thick-walled, swollen to more or less spherical (globose) cells embedded in a matrix, and extends into pale brown periphysoids at the upper inside margin.

These structures are faintly septate and not swollen at the tip, often appearing as a fringe on the surface and may close the ascomatal opening under dry conditions.

[11] Conidiomata, which produce asexual spores, are in the form of pycnidia (flask-shaped structures) that appear as slightly raised black warts.