Mycena overholtsii is a species of fungus in the family Mycenaceae which produces mushrooms which are relatively large for its genus, Mycena. The caps reach up to 5 cm (2.0 in) in diameter, with stems up to 15 cm (5.9 in) long. M. overholtsii grows on well-decayed conifer logs near snowbanks, during or just after snowmelt. It is commonly found in North America, though it has also been reported in Japan.Photograph: Noah Siegel, United States Forest Service