 Mycena cinerella , commonly known as the mealy bonnet , is an inedible species of mushroom in the family Mycenaceae . It is found in Europe and the United States , where it grows in groups on fallen leaves and needles under pine and Douglas fir . The small grayish mushrooms have caps that are up to 1 @.@ 5 cm ( 0 @.@ 6 in ) wide atop stipes that are 5 cm ( 2 @.@ 0 in ) long and 2 @.@ 5 mm ( 0 @.@ 10 in ) thick . Its gills are grayish @-@ white and adnate , with a " tooth " that runs slightly down the stipe . The fungus has both two- and four @-@ spored basidia . As its common name suggests , it smells mealy . 
