These keys to genera of the higher fungi were developed primarily for students in the courses on Basidiomycetes and on Higher Fungi taught on the Ann Arbor campus and at the Biological Station, respectively, of the University of Michigan. Although still far from perfect, the keys have passed through several biennial revisions and have proved to be useful in our teaching. The keys are not complete for the two classes of fungi (Ascomycetes and Basidiomycetes) included. An asterisk following the names of subclasses, orders, and families, indicates that these groups are treated no farther. Other groups are treated unevenly. In some cases, e.g., in the "Pyrenomycetes" and "Discomycetes," a key to only a few genera is included. In other cases, e.g., in the lamellate families of the Agaricales, coverage at the generic level is fairly complete, the genera are described briefly, and keys to infrageneric taxa are given. The selection of genera hs benn somewhat arbitrary, but the main criterion used is whether the genus is characterized by macroscopic fruiting structures which are likely to be encountered by students in temperate North America. The generic descriptions are not necessarily diagnostic in themselves; each must be considered in conjuntion with the appropriate family description which it qualifies and supplements.