Mushrooms are fleshy, spore-bearing fungi that are typically characterized by: A stem, or stipe A cap, or pileus Gills, or lamellae, on the underside of the cap Here are some other characteristics of mushrooms. (1) Development A thin membrane, called the universal veil, protects the mushroom as it develops. The veil eventually ruptures, leaving fragments on the cap. (2) Spores The gills produce microscopic spores that help the fungus spread. A single mushroom can produce millions of spores. (3) Appearance There are more than 10,000 known types of mushrooms. Some popular varieties include white button, cremini, portobello, shiitake, and chanterelle. (4) Nutrition Mushrooms are low in calories and fat, and contain many vitamins and minerals, including antioxidants, B vitamins, potassium, and vitamin D. (5) Texture Raw mushrooms have a sharp flavor, and a mild, nutty flavor when cooked. Their firm, chewy texture softens when cooking. Mushrooms are neither a plant nor animal food, but are considered a vegetable. They are used in many industries, including: Surgical dressings, Ink for writing and painting, Showpieces, Cleaning agents, Pesticides, and Anesthesia.