The book considers the importance of plants in Tolkien's conception of Middle-earth. It develops the theme that Middle-earth is our own world - and will awaken the reader to the connection between the plants of Tolkien's legendarium and those growing in our gardens and local natural areas of the Northern Hemisphere. It also demonstrates the connection between the various plant communities of Middle-earth and the elven and human cultures that occupy them, including those environments degraded by warfare, industrialization or pollution.

The heart of the book is an alphabetical listing, arranged by common names, of all of the plants mentioned in Tolkien's legendarium; for each of these plants the treatment will include: 1) common and scientific name, along with an indication of the family to which the plant belongs, 2) a brief quote from one of Tolkien's works in which the plant is referenced, 3) a discussion of the significance of the plant in the context of Tolkien's legendarium, 4) the etymology relating to both English common name and the scientific name, and where relevant, the name in one or more of the languages of Middle-earth, 5) a brief statement of the plant's distribution and ecology (along with mention of major species), 6) economic uses, both traditional and current, and 7) an easy-to-understand description of the plant. The book provides guidelines to the use of plant descriptions, and the few technical terms used are carefully defined. Many plants are illustrated by original artwork, in the style of a woodcut print. The description along with an identification key, when used with the illustrations, allow easy identification of each plant, adding to the reader's understanding and appreciation of Tolkien's works. A glossary of descriptive terms is also included.