Lactarius repraesentaneus, commonly known as the northern bearded milkcap, the northern milkcap, or the purple-staining milkcap, is a species of fungus in the Russulaceae family. It has a northerly distribution, and is found in temperate regions of North America and Europe, associated with spruce trees. Distinguishing features of its fruit body include the large orange-yellow cap up to 18 cm (7.1 in) wide, cream to pale yellow gills, and a yellow coarsely-pitted stem that is up to 12 cm (4.7 in) long and 3 cm (1.2 in) thick. Cut fruit bodies ooze a white latex that will stain mushroom tissue lilac to purple. Several chemicals have been isolated and identified from the fruit bodies that can modify the growth of plants, and the mushroom also has antibiotic activity against Staphylococcus aur