Peniophora quercina (Fr.) Cke. Eichen-Rindenpilz. Fruit body resupinate, forming ochraceous pink to purple grey patches 0.1–0.5mm thick which dry hard and brittle rolling away from the substrate and back on themselves to show the dark brown or black underside. Flesh relatively thick almost gelatinous, hyaline except for a narrow brownish zone adjacent to the substrate. Cystidia thick-walled, hyaline, fusiform, heavily encrusted with crystalline material, and often becoming buried as the hymenium thickens. Spores light red, curved cylindric, 8–12 x 3–4um. Habitat on dead branches of deciduous trees especially oak. Season all year. Common. Not edible. Distribution, America and Europe.