The forms and colors of mushrooms are diverse, but few approach the attractiveness of chicken of the woods mushroom, Laetiporus sulphureus.
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Chicken of the woods is a shelf mushroom found growing on the trunks of hardwood trees in the Northeast U.S. When young, like this one, the top is a neon orange, the underside a bright, clean yellow. It's perfectly edible for most folks, although the rare person may find it causes a mild reaction (perhaps swollen lips, nausea, dizziness, etc.), so try a little first before digging into a larger portion.
The variety is a polypore, i.e., it doesn't have gills but instead features pores on the underside.
Don't confuse it with hen of the woods, a.k.a. maitake, a completely different mushroom.