Peanut

A legume, not a nut

Despite being called a “nut,” peanuts are legumes — same family as beans, peas, and lentils. The defining feature of legumes is their relationship with nitrogen-fixing bacteria in their roots, which makes them one of the few plants that improve soil fertility as they grow.

Peanuts are uniquely geocarpic — after pollination, the flower stem grows downward into the soil, where the seed pods develop underground. This unusual development gives peanuts their alternative name “ground nuts.”

George Washington Carver’s project

The American agricultural innovator George Washington Carver developed over 300 peanut-based products at the Tuskegee Institute in the 1910s and 1920s — including peanut soap, peanut milk, peanut paper, peanut paint, and many cooking applications.

His work was driven by a specific Southern agricultural problem: cotton monoculture had depleted soils, and farmers needed alternative crops. Peanuts were ideal — they restored soil nitrogen, grew well in poor soil, and offered new income. Carver’s promotion of peanuts is credited with saving Southern agriculture in the early 20th century.

Allergy concerns

Peanut allergies are among the most common and dangerous food allergies — affecting roughly 1-2% of people in Western countries. Reactions can include:

• Oral itching
• Hives
• Anaphylaxis (life-threatening, requiring epinephrine)

The 2015 LEAP study showed that early peanut introduction (4–6 months of age) actually reduces the risk of developing peanut allergy by 80%, reversing decades of cautious advice. Modern guidelines recommend introducing peanuts to infants early.

Around the world

Peanuts feature in many cuisines:

• American — peanut butter, candy bars, baseball-park peanuts.
• West African — peanut sauce/groundnut stew (Senegalese mafé, Nigerian peanut soup).
• Indonesian — gado-gado, satay sauce.
• Thai — pad thai topping, peanut curries.
• Chinese — kung pao, smashed peanut sauces.
• Indian — chaat toppings, peanut masala curries.

The peanut is one of the most internationally adapted New World crops.