varied rag lichen (platismatia glauca) on a tree branch, close up

finland finnish heinola nordic parmeliaceae platismatia glauca scandinavia varied rag lichen abstract algae background barkdwelling betula biology birch branch closeup colour corticolous detail ecosystem environment europe foliose forest fungal fungi fungus green grow growing growth lichenology natural nature organism outdoor plant southern surface symbiosis symbiotic texture tree twig woods