Hericium erinaceus

Hericium erinaceus, commonly known as the lion's mane mushroom, yamabushitake (= ‘mountain priest mushroom’), bearded tooth fungus, bearded hedgehog, or old man's beard, is an edible mushroom belonging to the tooth fungus group. Native to North America, Europe, and Asia, it can be identified by its long spines (longer than 1 centimetre or 1⁄2 inch), occurrence on hardwoods, and tendency to grow a single clump of dangling spines. The fruit bodies can be harvested for culinary use.

H. erinaceus can be mistaken for other species of Hericium, which grow across the same range. In the wild, these mushrooms are common during late summer and fall on hardwoods, particularly American beech and maple. Usually H. erinaceus is considered saprophytic, as it mostly feeds on dead trees. It can also be found on living trees, so it may be a tree parasite. This could indicate an endophytic habitat. Outside of cultivation, lion's mane is usually associated with a tree wound and causes a white pocket rot. Decayed tissue becomes spongy and eventually disintegrates to form a cavity. The distinctive fruiting bodies (basidiocarps) generally appear near the edges of old wounds in the fall.