"Forest Trees of Illinois: How to Know Them" by Fuller, Mattoon, Miller, and Nuuttila is a scientific manual written in the mid-20th century. The work serves as a comprehensive guide to the identification of various tree species found in Illinois, describing their most important characteristics, uses, and habitats. This pocket manual is particularly focused on providing essential information for botanists, ecology enthusiasts, and forestry professionals. The opening of the manual introduces the reader to a variety of tree species native to Illinois, starting with detailed descriptions of individual trees such as the white pine and the bald cypress. Each entry presents key characteristics, including leaf types, bark texture, growth habits, and wood properties, alongside notes on their ecological settings and historical significance. This portion sets the groundwork for understanding the importance of these trees in both natural and cultivated environments, aiming to foster knowledge and appreciation of Illinois's forested landscapes. (This is an automatically generated summary.)