The mushroom whose long white spines resemble a mane is commonly called lion's mane, or Hericium erinaceus.
Its fruiting body is a rounded, white mass covered with crowded, dangling spines rather than the cap and gills seen on many familiar mushrooms. The spines often measure 1–5 centimetres or more, creating the shaggy appearance behind the common name.
Lion's mane is a tooth fungus that grows on hardwoods in North America and Eurasia. It is usually associated with dead or damaged trees and can cause white pocket rot. American beech and maple are among its notable hosts, and fruiting bodies commonly appear in late summer or autumn.
The species has several other names. Japan's yamabushitake refers to mountain ascetics, while the Chinese name hóutóugū means “monkey-head mushroom.” It is edible and used in traditional Chinese medicine, but many modern supplement claims remain inadequately established by clinical evidence.