“The past half century has been a most astounding time for those of us fortunate enough to have been involved in research and teaching about tall fescue. The whole 35-year process has seemed akin to a complicated detective novel, complete with some distracting issues and alleged but innocent perpetrators.” -H.A. Fribourg, D.B. Hannaway, and C.P. West, Editors The story of tall fescue is not just a story for forage and turf scientists, but for scientists. Beginning with the discovery of a green Kentucky pasture, and the spiral of poor animal performance that followed, the study of tall fescue is an ongoing puzzle, with an intricate series of biochemical and physiological processes and interactions among animals, plants, fungi, and the environment. The changing understanding of tall fescue reveals how science develops and moves through disciplines, challenges, and new advances in research and technology. Topics covered include the origin, history, and classification of tall fescue; its ecological suitability and adaptation; methods for establishment and management; its pests and control methods; its utilization, quality, and anti-quality factors; genetic improvement; seed production and marketing; and turf and conservation uses. Tall fescue is the most important cultivated pasture grass in the United States, and it is increasingly important in other humid temperate regions in the world. Its agronomic characteristics make it the primary choice of many managers who desire a forage suitable for a variety of animals under diverse and challenging climatic and soil conditions, or who want a perennial plant for functional or aesthetic soil cover in many situations.