Armillariella tabescens

Common Name: None.
Description: Cap 3-10 cm across, convex then expanded to flat or irregular; margin uplifted in age; ochre-brown with darker, cottony scales; dry. Stem 70-200 by 5-15 mm high and wide.
Habitat: in dense clusters attached to living or dead stumps and roots or over buried woods, especially oak. Common. Found widely distributed in eastern North America, west to Kansas and Texas.
Edible: when cooked, but has been known to cause stomach upset.

Source: Mushrooms of North America by Roger Phillips.