Gymnopus (Pers.) Roussel, Fl. Calavad. ed 2. 62. 1806.
Basidiomata marcescent, tough, or membranous, rarely putrescent and fleshy; spore deposit white to cream colored; spores inamyloid, acyanophilous. Type species: Gymnopus fusipes (Pers.) S. F. Gray, Nat. Arr. Brit. Pl. 1: 604. 1821. Key to Sections of Gymnopus For a French translation by Roland Labbé, go here. Includes key to sections and species.
1. Pileus with violet pigments which become blue in alkali . . . . section Iocephalae
1. Pileus without violet pigments; reaction to alkali is various, but not blue . . . . 2
2. Hyphae of the pileus surface repent (end cells rarely suberect), generally radially oriented, cylindric; diverticulate elements and branchlets sometimes present . . . . section Vestipedes
2. Hyphae of the pileus surface frequently branched, with short, broad cells without radial orientation . . . . 3
3. Stipe strongly fusoid, deeply radicating on or around Quercus (rarely Betula or Fagus) roots and stumps . . . . section Striipedes (Collybia fusipes, Old World) IMAGE ONLY
3. Stipe not strongly fusoid and radicating, but sometimes on Quercus . . . . section Levipedes