Small, with a bell-shaped, reddish brown cap; bleeds dark red when cut. Usually grows in clusters on decaying wood. June–September. Cap egg-shaped, becoming bell-shaped to conical, with a central knob and upturned margin; reddish pink when dry, becoming darker reddish brown when moist, and paler gray toward the lined margins; texture dry, becoming polished and radially lined; when cut, the flesh bleeds a dark, blood red liquid. Young specimens usually have a powdery bloom on the cap. Gills narrow to moderately broad; spacing close to nearly distant; whitish, staining a reddish brown; gills attached. Stalk skinny; pinkish to reddish tan; covered with fine hairs; longer, coarse hairs at the base; when young, the cut stalk bleeds dark red. Spore print white. Spores magnified are broadly elliptical, smooth, colorless. This little mushroom is easy to identify because of the bell-shaped cap and oozing, blood red liquid.
Lookalikes: Other Mycena species—none, however, “bleed” like this species.