Mycena epipterygia, the yellowleg bonnet, is a species of fungus in the family Mycenaceae, native to Europe. It grows on the floor of deciduous and coniferous woodland as well as on acid grassland, and among mosses, as seen here at Erbach an der Donau, in Baden-Württemberg, Germany. The sticky, bell-shaped cap becomes more convex with age, and varies in colour, the slender cylindrical stem being yellowish-green, which helps to distinguish this fungus from other species. Some parts of the fungus, including the mycelium, are bioluminescent.Photograph credit: Holger Krisp