Thelenella

Thelenella is a genus of lichen-forming fungi in the family Thelenellaceae. These inconspicuous lichens form thin, crust-like growths that are tightly attached to their substrates and appear as dull whitish, pale grey, or light brown patches. Species of Thelenella are commonly found in damp, shaded environments where they grow on tree bark, living leaves, moss cushions, rock faces, and moss-rich soil. The genus is distinguished by its thick-walled fruiting bodies that are mostly embedded within the lichen crust and contain multicellular spores with multiple cross-walls....read more on Wikipedia.