Mycena citricolor is a plant pathogen producing leaf spots on coffee plants. This fungus causes the disease commonly known as American Leaf Spot. Mycena citricolor affects coffee plants, primarily in Latin America, but can grow on other plants as well. This fungus can grow on all parts of the coffee plant including the leaves, stems and fruits. When grown on the leaves, Mycena citricolor results in leaves with holes that often fall from the plant.
The Mycena fungus can be identified growing on subcircular, brown spots on coffee leaves. The brown spots are caused be the presence of the saprotrophic fungus and by looking at the leaves closely, small mushrooms with luminescence can be seen.  The fungi's luminescence is active in the presence and absence of light.  Mycena citricolor's luminescence is also affected by the temperature of its environment.