Membrane Dog Lichen

Peltigera is a genus of approximately 91 species of lichenized fungi. Commonly known as the dog lichen, lichens of Peltigera are often terricolous (growing on soil), but can also occur on moss, trees, rocks, and many other substrates in many parts of the world.
Many Peltigera species are cyanolichens (having a cyanobacteria symbiont), but some Peltigera spp. have only an algae symbiont, and others have both. Because of their ability to fix nitrogen from the atmosphere, such lichens are influential in soil composition and generation
P. Membranacea is a large "dog-lichen" with the upper surface of fresh thallus bluish- to brown-grey, ash-grey when dry, densely felted-tomentose, bullate, lacking isidia; lower surface white-tomentose, with unbranched, "fang-like" rhizines with fine, spreading, "bottle-brush" hyphal terminations (lens needed)