Lepiota castaneidisca is a species of agaric fungus in the family Agaricaceae. Formally described in 1912, it was for a long time considered the same species as the similar Lepiota cristata until molecular analysis reported in 2001 demonstrated that it was genetically distinct. It is most common in coastal and northern California, and has also been recorded in Mexico. A saprobic species, it is usually found under redwood and Monterey cypress. Its fruit bodies (mushrooms) have white caps with an orange-red to orange-brown center that measure up to 3.2 cm (1.3 in) wide. The cream-colored to light pink stems are up to 6.5 cm (2.6 in) long by 0.2–0.6 cm (0.1–0.2 in) thick, and have a ring. L. castaneidisca can be distinguished from other similar Lepiota species by differences in habitat, macro