Dryad's saddle

Description:

It is an basidiomycete bracket fungus, also known as Pheasant's back mushroom. It commonly fruits in the spring, occasionally during autumn, and rarely during other seasons. Many mushroom hunters will stumble upon this when looking for morels during the spring as both have similar fruiting times, and this fungus can grow to a noticeable size of up to 50 cm across.

Habitat:

It has a widespread distribution, being found in North America, Australia, Asia, and Europe, where it causes a white rot in the heartwood of living and dead hardwood trees. It plays an important role in woodland ecosystems by decomposing wood, usually elm, but is occasionally a parasite on living trees. Other tree hosts include ash, beech, horse chestnut, lime, maple, planetree, poplar, and willow.

Notes:

The name "Dryad's saddle" refers to creatures in Greek mythology called Dryads who could conceivably fit and ride on this mushroom, whereas the pheasant's back analogy derives from the pattern of colors on the bracket matching that of a pheasant's back.