Grifola frondosa (also known as hen-of-the-woods, maitake (舞茸, "dancing mushroom") in Japanese, ram's head or sheep's head) is a polypore mushroom that grows at the base of trees, particularly old growth oaks or maples.

Like the sulphur shelf mushroom, G. frondosa is a perennial fungus that often grows in the same place for several years in succession.

[3] The undersurface of each cap bears about one to three pores per millimeter, with the tubes rarely deeper than 3 mm (1⁄8 in).

Edible species which look similar to G. frondosa include Meripilus sumstinei (which stains black), Sparassis spathulata[4] and Laetiporus sulphureus, another edible bracket fungus that is commonly called chicken of the woods or "sulphur shelf".

[5] It occurs most prolifically in the northeastern regions of the United States, but has been found as far west as Idaho.