A key to the species of Cystolepiota Sing., and descriptions of C. cystidiosa (A.H. Smith) M. Bon, C. adulterina (F. Møller) M. Bon, C. hetieri (Boud.) Sing., and C. moelleri Knudsen are given. Four taxonomic revisions were made: 1. type studies of C. cystidiosa, C. luteicystidiata (D. Reid) Knudsen, and Lepiota lycoperdoides Kreisel have revealed these three species to be conspecific; 2. C. adulterina var. reidii (M. Bon) M. Bon is synonymized with C. adulterina; 3. the type collection of C. subadulterina M. Bon appeared to be a mixed collection of C. hetieri and C. adulterina, and 4. the genus Pulverolepiota M. Bon, created to accommodate C. pulverulenta (Huijsman) Vellinga, is reduced to a section of Cystolepiota.