A wood-rotting fungus that grows on dry, well-rotted oak. Mushrooms in large patches, up to several feet across, each small, irregular, glossy white (or with pastel tints), black or dark brown on the sides. The overall effect is of white tile with dark grout. Persists year-round.

Not common, but to be looked for in the southeast area of the Park where a number of oaks have fallen.

Unmistakable, although many people likely think that it is artificial and not a natural organism at all.