Lenzites betulina

Common Name: None.
Description: Fruit body annual; no stem; broadly attached or with a small stemlike attachment. Bracket up to 8 cm across, 5 cm wide, 2 cm thick flat, semicircular or fan-shaped, with an even or lobed margin; upper surface white, cream, grayish, or brownish, older specimens often have a green tinge because fo algae growing in the fine hairs; tough and leathery with an uneven surface, concentrically grooved, zoned and hairy.
Habitat: singly or in overlapping groups on hardwoods and coniferous wood. Common. Found in midwestern and eastern North America, the Pacific Northwest, and California, but extremely rare elsewhere.
Edible: Not edible.

Source: Mushrooms of North America by Roger Phillips.