Calories in Peanuts

What makes peanuts so powerful?

Peanuts are not nuts at all—they are legumes, botanically closer to lentils and chickpeas than to walnuts or pecans. What makes them genuinely unusual is a reproductive process called geocarpy. After the peanut plant's yellow flowers are self-pollinated above ground, the fertilized ovary elongates into a structure called a peg, which bends downward and pushes several centimeters into the soil. Only underground, in darkness, does the peg develop into the familiar pod containing the seeds we eat. This subterranean fruiting is rare among major crop plants. Peanuts also accumulate resveratrol—the same antioxidant associated with red wine—in their skins, at levels comparable to or exceeding those in grapes. The plant (Arachis hypogaea) originated in South America, likely in the foothills of the Andes in what is now Bolivia or northern Argentina, and was spread worldwide by European colonists and African agricultural traditions, becoming a staple across West Africa, India, China, and the American South.