Maitake

Grifola frondosa is a polypore mushroom that grows in clusters at the base of trees, particularly oaks.

The mushroom is commonly known among English speakers as hen-of-the-woods, ram's head and sheep's head. In the United States' supplement market, as well as in Asian grocery stores, the mushroom is known by its Japanese name maitake (舞茸), which means "dancing mushroom".

The fungus is native to the northeastern part of Japan and North America, and is prized in traditional Chinese and Japanese herbology as a medicinal mushroom, an aid to balance out altered body systems to a normal level. Due to the taste and texture of the mushroom, it is widely eaten in Japan, although the mushroom has been alleged to cause allergic reactions in rare cases.

The sclerotia from which hen of the woods arises have been used in traditional Chinese and Japanese medicine to enhance the immune system.

In Japan, the Maitake can grow to more than 50 pounds (20 kilograms), earning this giant mushroom the title "King of Mushrooms." Maitake is one of the major culinary mushrooms used in Japan, the others being shiitake, shimeji and enoki. They are used in a wide variety of dishes, often being a key ingredient in nabemono or cooked in foil with butter.