Lactarius chelidonium is a member of the large milk-cap genus Lactarius in the order Russulales. It was first described by American mycologist Charles Horton Peck in 1870.

Lactarius paradoxus is a North American member of the large milk-cap genus, Lactarius, in the order Russulales. The mushroom is blue-green to gray, staining green and bleeding red latex. It is edible