Mycena cinerella, commonly known as the mealy bonnet, is an inedible species of mushroom in the Mycenaceae family. 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 wide atop stems that are long and thick. Its gills are grayish-white and adnate, with a "tooth" that runs slightly down the stem. The fungus has both two- and four-spored basidia. As its common name suggests, it smells mealy.