Basidiocarps: annual brackets, applanate (flattened) to slightly convex, dimidiate, fan shaped to rounded, up to 15cm wide and long, 1 to 5 cm thick, fleshy and flexible when fresh then hard but friable when dry and light of weight; upper surface finely velutinate when young but soon glabrous, at first whitish, then yellow and finally brown becoming darker from the base with age, often pitted and slightly tuberculate; margin rounded, finely pubescent and pale brown; pore surface smooth and white when young, darker when bruised, later dirty brown and cracked. Pores: circular, 2-4 per mm. Context: much thicker than tubes, white, hard and tough up to 4 cm thick; tube layer concolorous with pore surface, up to 4 mm thick. Hyphal system: dimitic (consisting of two types) in context, monomitic (consisting of one type) in trama. Cystidia: absent, fusoid cystidioles present. Basidia: 25-30 x 7-9 μm, narrowly clavate, four spored, with a basal clamp. Spores: 6-8 x 2.5-3.5 μm, cylindrical, fusiform, tapering to the base, usually characteristically bent close to the apex, hyaline, smooth, thin walled.