Xylaria hypoxylon

Common Name: None.
Description: Fruit body 2-8 cm high, subcynlindrical at first, becoming flattened and branched into an antler shape; the upper branches powdered white, finally tipped black when mature; lower part black and hairy.
Habitat: on dead wood. Common. Found throughout North America.
Edible: Not edible.

Source: Mushrooms of North America by Roger Phillips.