Cortinarius lacustris is an inedible species of mushroom-forming fungus belonging to the family Cortinariaceae and found mainly in oak groves in deciduous forests.
Description The mushroom cap is a reddish, cinnamon brown with a diameter between . It has a cylindrical stipe that turns to a purple-black when reacting to potassium hydroxide solution exposure. The partial veil has a slight yellow colour. The ellipsoid spores measure between 8.5–11 μm by 5–6 μm.
See also List of Cortinarius species
References