[1][2] These lichens typically have a thin, crust-like thallus that often grows beneath the surface of tree bark or rocks in tropical rainforests and coastal areas.

The genus has had an uncertain taxonomic history since its original description in 1860, but recent genetic studies have placed it in its own distinct group within the fungal class Eurotiomycetes.

This order would include lichen-forming fungi (Celothelium) as well as some plant pathogens like Phaeomoniella chlamydospora and Dolabra nepheliae.

[5] Celothelium is characterised by a crusty (crustose) thallus, which is often difficult to see because it grows mostly beneath the surface of its substrate, such as tree bark or rock.

[8] Surrounding groups of perithecia is a dark layer known as the involucrellum, which is composed of both bark material and reddish-brown fungal threads (hyphae).

The exciple is made of pale to brown fungal threads mixed with bark cells, forming a tightly woven structure.

The spores inside the asci are thread-like to needle-like, translucent (hyaline), and divided by multiple internal partitions (multiseptate).