Trametes versicolor

Trametes versicolor – also known as Coriolus versicolor and Polyporus versicolor – is a common polypore mushroom found throughout the world. Owing to its shape being similar to that of a wild turkey's tail feathers, T. versicolor is most commonly referred to as turkey tail.

Although polysaccharide-K, an extract of T. versicolor, is approved in Japan as an adjuvant therapy in cancer treatment, it is not approved in the United States for treatment of cancer or any clinical condition. Extracts of turkey tail or the mushroom itself are commonly marketed as a dietary supplement for various health benefits, and quality can vary due to inconsistent processing and labeling.

Meaning 'of several colors', versicolor accurately describes this fungus that displays a unique blend of markings.

The fruiting body is somewhat tongue-shaped, with no discernable stalk, and the tough flesh is 1–3 millimetres (1⁄16–1⁄8 in) thick. The cap is flat, up to 10 centimetres (4 in) across. It is often triangular or round, with zones of fine hairs coloured rust-brown or darker brown, sometimes with black zones. Underneath a layer of tomentum is a black layer, topping the whitish flesh. Older specimens can have zones with green algae growing on them.

The bottom surface of the cap shows typical concentric zones of different colors, with the margin always the lightest. There are 3–5 pores per mm. They are whitish to light brown, with pores round and with age twisted and labyrinthine.

One similar-looking mushroom is Stereum ostrea (false turkey tail).

Other similar species include Trametes betulina, T. hirsuta, T. ochracea, T. suaveolens, Bjerkandera adusta, Cerrena unicolor, Lenzites betulina, and Stereum hirsutum. Other species of Stereum are similar, typically with a smooth undersurface, as well as some species of Trichaptum.

T. versicolor commonly grows in tiled layers in groups or rows on logs and stumps of deciduous trees. It is a white rot fungus which degrades lignin from lignocellulosic materials, such as wood.