In this collection of natural-history essays, biologist Joan Maloof embarks on a series of lively, fact-filled expeditions into forests of the eastern United States. Through Maloof’s engaging, conversational style, each essay offers a lesson in stewardship as it explores the interwoven connections between a tree species and the animals and insects whose lives depend on it—and who, in turn, work to ensure the tree’s survival. Never really at home in a laboratory, Maloof took to the woods early in her career. Her enthusiasm for firsthand observation in the wild spills over into her writing, whether the subject is the composition of forest air, the eagle’s preference for nesting in loblolly pines, the growth rings of the bald cypress, or the gray squirrel’s fondness for weevil-infested acorns. With a storyteller’s instinct for intriguing particulars, Maloof expands our notions about what a tree “is” through her many asides—about the six species of leafhoppers who eat only sycamore leaves or the midges who live inside holly berries and somehow prevent them from turning red. As a scientist, Maloof accepts that trees have a spiritual dimension that cannot be quantified. As an unrepentant tree hugger, she finds support in the scientific case for biodiversity. As an activist, she can’t help but wonder how much time is left for our forests.