This means they typically form a symbiotic relationship with a photosynthetic partner, or in some cases, parasitise other lichens.

Its appearance can range from continuous to patchy, and it may be cracked or broken into small, tile-like segments (areolate).

Often, there is a prothallus, which is a preliminary growth stage that typically appears dark and may form a thin outline or a more extensive network between the areoles.

The surface of the thallus can be colourless or various shades of brown, yellow, or green, and it may be smooth, rough, or covered in a fine powder (pruinose).

[8] The primary photobiont (symbiotic partner conducting photosynthesis) in Buellia is usually a species of Trebouxia.

The conidiophores (structures that bear the conidia) within these pycnidia can vary in length and branching.