“Much as peaches, once introduced, were spread across North America by indigenous people in a matter of decades, the pollen record shows that hazel (Corylus avellana) suddenly becomes ubiquitous across Europe as soon as the climate warmed, brought to every corner of the continent by hunter-gatherers. Hazel was the original Tree of Life for Mesolithic Europeans. The nuts are about 60% fat and 20% carbohydrates, and contain a wide range of proteins, vitamins and minerals - a few handfuls can cover most of a person’s daily energy needs. Its branches, tall and flexible but slender enough to cut with a flint axe, were used for tools and firewood. Mesolithic thatched huts were often made with hazelwood beams. From cradle to grave, the people of Mesolithic Europe relied on hazel more than any other single plant. Excavations of habitation sites from this period can turn up hundreds of thousands of roasted hazelnut shells. For over five thousand years, this single plant was the lifegiver to nearly all of Europe’s people.”

— Max Paschall, The Lost Forest Gardens of Europe