Lepraria lobificans - a leprose lichen.
The thallus of a leprose lichen has a powdery appearance. Often Lepraria thalli are composed of tiny granules, with the mass of granules seated on a woolly layer of hyphae in some species. Each granule is composed of fungal hyphae and some photobiont cells and in many species the individual granules are fuzzy because fungal hyphae extend out from the surface of each granule. Consequently the photographs of Lepraria species often give the impression of being out of focus.

Photographer: Heino Lepp