Tooth fungus

From Freepedia

Tooth fungi are a relatively small group of fungi whose mushroom bears its spores on a hymenium - a layer of "mother cells" - that grow on the outside of tooth-like spines. These spines can either grow in branches from the side of the host (as in Hericium coralloides) or on the underside of the cap (as in the Hedgehog fungus, Hydnum repandum). Most tooth fungi are hard and inedible. However, a few (such as the bearded tooth Heracium erinaceum) are not. These are often prized as easily identifiable edibles. These mushrooms will often get stuck on your socks while hiking, occasionally drawing blood.