Button mushrooms have grown wild since prehistoric times and were revered by the Egyptians, who believed the mushrooms gave the consumer special powers or eternal life. These cute, little mushrooms are tiny thumbnail-sized with smooth rounded caps and short truncated stems. Plus, their flavor is mild when raw and more fragrant and meaty when cooked. Considered to be calorie-free, White Button mushrooms are a good addition to your daily diet. Besides, they are rich in potassium, selenium, protein, and cancer preventing antioxidants. According to one study in 2012, eating mushrooms may also help prevent respiratory infections. Since White Button mushroom are small, they can be served whole in soups and stews or salads.