This dictionary, now in its sixty-fifth year, contains more than 21 000 entries and provides the most complete listing available of generic names of fungi, their families and orders, their attributes and descriptive terms. All organisms traditionally studied by mycologists are covered including lichens, mushrooms, slime moulds, water moulds and yeasts. For each genus, the authority, the date of publication, status, systematic position, number of accepted species, distribution, and key references are given. Diagnoses of families and details of orders and higher categories are included for all groups of fungi. In addition, there are biographic notes, information on well-known metabolites and mycotoxins, and concise accounts of almost all pure and applied aspects of the subject (including citations of important literature). All information has been updated as necessary since the publication of the ninth edition in 2001. In addition, this tenth edition has the following new features: a completely new classification of the Kingdom Fungi based on recent multi-gene phylogenetics research; a major revision of the classification of the Basidiomycota and substantial modification of the 'basal' groups; further integration of anamorphic and teleomorphic genera in the classification; enhanced distinctions between the true fungi and unrelated groups traditionally studied by mycologists; and improved information on references to publications.