The epic story of the planet's oldest trees and the making of the modern world. Humans have always revered long-lived trees. But as historian Jared Farmer reveals in Elderflora, our veneration took a modern turn in the eighteenth century, when naturalists embarked on a quest to locate and precisely date the oldest living things on earth. The new science of tree time prompted travellers to visit ancient specimens and conservationists to protect sacred groves. Exploitation accompanied sanctification, as old-growth forests succumbed to imperial expansion and the industrial revolution. Taking us from Lebanon to New Zealand to California, Farmer surveys the complex history of the world's oldest trees, including voices of Indigenous peoples, religious figures, and contemporary scientists who study elderflora in crisis. In a changing climate, a long future is still possible, Farmer shows, but only if we give care to young things that might grow old. Combining rigorous scholarship with lyrical writing, Elderflora chronicles the complex roles ancient trees have played in the modern world and illuminates how we might need old trees now more than ever. Historian Jared Farmer tells the globe-spanning story of humanity's deep fascination with the oldest living trees, the lessons in survival they offer us, and how to alter our behaviour so that the young trees of today can become ancient themselves.