Cap 200-300 mm broad x 70-100 radius x 40-60 mm thick, irregularly semicircular to shelflike, cracked, sulcate, glabrous, brown to dark brown; flesh tough and woody, yellowish brown, zonate. Pores round, 7-9 per mm, yellow to yellowish brown; tubes in several layers (perennial), each layer 2-3 mm thick. Stem absent. Spore Deposit white. Edibility: too tough to eat.