Collybia Omphalina Pileus up to 3 cm, deeply umbilicate, light brownish olive in depression, margin cream buff to isabelline, very minutely tomentulose, otherwise smooth, margin not striate although appearing so from the gills underneath in certain lights; gills white, narrow, very close, sinuate decurrent by a tooth; stipe white shading to isabelline 2.5 cm x 4-2 mm tapering downward Limon, Siquirres, Castilla, 20 m., Dodge & Goerger 7-23