This second edition of Sedges: Cyperus to Scleria brings up to date the identification of species of sedges in Illinois (except Carex) since publication of the first edition in 1976. During the intervening years, several additions to the sedge flora of Illinois have been made, and many new distributional records have been added. Also, a large number of nomenclatural changes have taken place, resulting in several alterations of scientific names. New illustrations have been provided for all of the additions.  In his introductory material, Robert H. Mohlenbrock discusses the morphology of sedges and the habitats where they can be found. Although the semitechnical keys and descriptions are familiar to experienced botanists, he has simplified them as much as possible to accommodate the novice in sedge identification. He has also included a new key to the sedges and to each genus in which additional species have been added. For each species, Mohlenbrock has provided a description, statement of habitat and range, Illinois distribution map, discussion, synonymy, and line illustrations showing its diagnostic features. Sedges: Cyperus to Scleria contains 128 illustrations.