Lobarina

Lobarina is a genus of lichen-forming fungi in the family Peltigeraceae. Lobarina resembles the related genus Lobaria in lobe arrangement and medullary chemistry, but its thallus has shallow pits and a markedly denser tomentum on the underside, leaving white, rounded patches that do not align with the surface depressions. The genus occurs mostly in temperate and tropical mountain forests of the Northern Hemisphere, where species grow on tree bark in moist, shaded environments. Members of Lobarina are cyanolichens, meaning they partner with cyanobacteria that can fix nitrogen from the air. These lichens are particularly vulnerable to grazing by snails and slugs, which can consume entire thalli within days....read more on Wikipedia.