Cortinarius acystidiosus is an uncommon Cortinarius mushroom reported from East of the Rocky Mountains. This example was found with hardwoods (lots of oak) with pine nearby. Limestone soil and growing beside a limestone rock. Initially appears white, but upon closer inspection the cap has a slight yellow tinge with light orange dots. Cap is smooth. Stem is white with a bulbous base. Cortina is white, eventually brownish from the rusty brown spores this mushroom produces. Found in August. Monroe County, Indiana.