The lichen, in a single body, unites the two great pathways of life: the so-called grazing food chain based on the building up of beings, and the detrital food chain based on taking them apart. Producers and decomposers, the light and the darkness, the givers and receivers wrapped in each other’s arms, the warp and the weft of the same blanket so closely woven that it’s impossible to discern the giving from the taking. Some of earth’s oldest beings, lichens are born from reciprocity. Our elders share the teachings that these rocks, the glacial erratics, are the oldest of grandfathers, the carriers of prophecy, and our teachers.