Pterygiopsis

Pterygiopsis is a genus of lichen-forming fungi in the family Lichinaceae. It contains 12 species. These lichens form thin, blackish crusts that cling tightly to rock surfaces, especially in damp seepage zones or along stream margins, and develop pinpoint brown disc-like fruiting bodies on their surface. The genus is typically found in semi-aquatic to fully aquatic habitats, where the lichens lack distinct outer protective layers but have a slightly gelatinous texture when wet....read more on Wikipedia.