### Identification To spot a Lion’s Mane (*Hericium erinaceus*), look for a "frozen waterfall" clinging to the side of a tree. Unlike typical mushrooms with caps and stems, this species forms a dense, unbranched globular mass of white, icicle-like spines (teeth) that can reach up to 5cm in length. In its prime, it is a brilliant, snowy white, though it fades to a creamy yellow or tan as it ages. To distinguish it from its cousin, the Coral Tooth (*H. coralloides*), look at the structure: *H. erinaceus* grows as a single, solid clump, whereas its relatives branch out like delicate marine coral.
### Habitat & Range This striking fungus is a resident of the Northern Hemisphere, spanning North America, Europe, and Asia. It is a specialist of deciduous forests, showing a marked preference for mature oak, beech, and maple trees. While it can be found on fallen logs, it is famously known for appearing high up on the trunks of living hardwoods—sometimes 40 feet in the air—making it a prize for the binocular-wielding naturalist.
### Behaviour Lion’s Mane is a "wound-dweller." It acts as a heart-rot fungus, entering a tree through a scar or a broken limb. It is a patient inhabitant; once established, it may fruit from the exact same crevice year after year. For the field observer, its appearance is a seasonal highlight of late summer and autumn, often emerging after heavy rains when the humidity is high.
### Diet As a saprotroph and a weak parasite, *Hericium erinaceus* feeds by secreting specialized enzymes that break down the "bones" of the tree—complex polymers known as lignin and cellulose. By digesting these materials, it slowly decays the heartwood, recycling ancient nutrients back into the forest ecosystem.
### Fascinating Fact This mushroom is a literal "brain-booster!" It contains unique compounds called hericenones and erinacines that can cross the blood-brain barrier. These chemicals stimulate the production of Nerve Growth Factor (NGF), essentially helping the human brain to repair, maintain, and even grow new neurons.