Peanuts are not nuts. They are legumes that grow underground, like peas and beans.
After the peanut plant flowers, the stalk bends down and pushes the developing pod into the soil, where it ripens. Real tree nuts, such as hazelnuts and walnuts, grow on trees.
Why is this true?
Peanuts belong to the same plant family as lentils, chickpeas and soybeans. That is also why a peanut allergy is not the same as a tree-nut allergy, even though the two often occur together.
More facts in this category
More about food
Food facts sit right where biology, chemistry and history overlap. A fruit that is technically a berry, a spice worth more per gram than silver, a sweetener that never spoils in a sealed jar — the reasons usually come down to sugar, acid, water and how long humans have been moving plants around the planet. Each entry explains the mechanism in plain language, and links to a source if you want the longer version.