Mycena vitilis, commonly known as the snapping bonnet, is a species of inedible mushroom in the family Mycenaceae. It is found in Europe and North America, where it grows on the ground among leaves in damp places, especially under alder. The small pale gray to whitish fruit bodies are usually attached to small sticks buried in the leaves and detritus. They are distinguished by their long, slender stems that root into the ground, and by the grooved cap that reaches diameters of up to 2.2 cm (0.9 in). The grayish-white gills on the underside of the cap are distantly spaced, and adnately attached to the stem. M. vitilis contains strobilurin B, a fungicidal compound with potential use in agriculture.