The caps are usually 4 ½ to 6 inches wide (12 to 15 cm.) When the mushroom is very young, the cap is more like an oval knob than it is rounded. As the mushroom matures, the caps open up to become as flat as a plate. Cultivated ones are harvested much smaller, while the cap is still closed and it looks like a button mushroom with pale yellow colouring. The caps are white or pale yellow; they start off pale yellow and get whiter as the mushrooms mature.
The stems are long.
Horse Mushrooms are more tasty than regular white mushrooms, and have a faint smell of anise.
Don’t eat raw, cook first.
Amateurs picking it in the wild risk confusing it with the poisonous Yellow Staining Mushroom, which is similar in appearance.