Rigidoporus ulmarius (Sowerby) Imazeki (illustrated 25% life size) Bracket 12–50×6–15cm across, 4–8cm thick; white to ochraceous, becoming dirty brown with age; hard and woody, surface knobbly, concentrically ridged. Tubes 1–5mm long in each layer; pinkish to orange when young, browning with age, each layer separated by a thin band of white flesh. Pores 5–8 per mm; red-orange, fading to clay-pink or buff with age. Spores 6–7.5¼ in diameter, globose; pale yellow. Hyphal structure monomitic; generative hyphae without clamps. Habitat at the base of trunks of deciduous trees, usually elm; perennial. Occasional. Not edible.