1. Spore deposit white to ivory yellow or buff, rarely pink; spores neither cyanophilous nor dextrinoid; basidiocarps membranous to marcescent . . . . 2

2. Basidiomata white to gray, typically arising from a sclerotium or blackened fungous remains, rarely in humus, with filiform stipe and small pileus (<20 mm); spores typically less than 6 x 3 µm . . . . 3

3. Stipe producing narrow side branchlets with conidia; sclerotia black to dark gray . . . . Dendrocollybia

3. Stipe lacking side branchlets; sclerotia dark yellow, orange to reddish brown or absent . . . . Collybia

2. Basidiomata neither arising from a sclerotium nor blackened fungous remains, if in humus, stipe never filiform and with pileus >20 mm; spores usually >6 µm . . . . Gymnopus