Edible lichen

Edible lichens are lichens that have a cultural history of use as a food. Although almost all lichen are edible (with some notable poisonous exceptions like the wolf lichen, powdered sunshine lichen, and the ground lichen), not all have a cultural history of usage as an edible lichen. Often lichens are merely famine foods eaten in times of dire needs, but in some cultures lichens are a staple food or even a delicacy.