Lichens are composite lifeforms, usually comprised of a fungus and algae, or a fungus and cynobacterium. Generally, the fungus provides shelter and needed minerals, and the algae, using photosynthesis, provides food. This community is on Chatsworth Formation sandstone at Sage Ranch.
There is a tendency to think of living things, including ourselves, in the singular. But most life is a intertwined assemblage of cooperating organisms, from the very small to the very large, living in harmony. Circle within circle, life within life.