lichen
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.fungi in the family Physciaceae. The genus has a widespread distribution and contains about 265 species. It is hypothesized that a few saxicolous species common to dry regions of western North America, southern Europe, North Africa and central Asia may date back 240 million years to the Middle Triassic.