Mycena luteopallens

Common Name: Walnut Mycena
Description: Cap 1-1.5 cm across, ovate to bell-shaped, then soon flattened;; bright yellow to orange, fading to white; slightly downy then smooth, translucent when wet. Stem 40-100 by 1-1.5 mm high and wide.
Habitat: only found growing on the remains of hickory and walnut shells. Very common. Found throughout eastern North America, west to Michigan.
Edible: unknown.

Source: Mushrooms of North America by Roger Phillips.