Climacodon septentrionale Shelving Tooth
Fruitbodies are in tight, shelving layers. Brackets are broadly attached, 10-28 cm across by up to 12 cm wide and 5 cm thick at the base, yellowish white, becoming tan in age and covered with densely-matted hairs. Flesh is thick, white, tough and fibrous. Spines are up to 2 cm long, tightly packed, whitish, ageing tan. Widespread and not uncommon, it fruits on the trunks of living hardwood trees especially maples. Also known as Steccherinum septentrionale.Not obviously a tooth fungus until you take a closer look!