Fries (1821: 11) established Agaricus series Derminus tribus Inocybe, which was later elevated by him to generic rank (Fries, 1863: 346). Originally Fries based his circumscription of Inocybe solely on macroscopical characters; when it was raised to generic status Fries added that the spores of all Inocybe species were seemingly rough (’sporae scabrae videntur omnibus Inocybis communes’). Almost certainly this was not based on original observation, as Fries considered the use of the microscope unnecessary, but the result of an uncritical appraisal of observations by Berkeley (1860). The relevance of Fries’s statement regarding the typification of Inocybe is discussed on p. 29. Although the genus Inocybe is easily recognisable by macroscopical characters, judging from the fact that the generic concept has scarcely changed to the present day, the delimitation of species is considerably more difficult. The number of species increased continually from 1821 onwards. Massee (1904) published a world monograph of the genus but his work unfortunately lacks precision and it is moreover outdated. Important regional work on the genus has been carried out by Heim (1931) and Kühner (in Kühner & Romagnesi, 1953) in France; Alessio (1980) in Italy; Enderle & Stangl (1981) and Stangl & Enderle (1983) in Germany; Kauffman (1924), Stuntz (1947, 1954), and Grund & Stuntz (1968, 1970, 1975, 1977, 1980, 1981, 1983, 1984) in North America; and Horak (1978, 1979, 1980, 1981) in Australia and Asia.