Peanut Anatomy

The peanut is unusual because it flowers above the ground, but fruits below the ground. Typical misconceptions of how peanuts grow place them on trees (like walnuts or pecans) or growing as a part of a root, like potatoes.

Peanut seeds (kernels) grow into a green oval-leafed plant about 18 inches tall which develop delicate flowers around the lower portion of the plant. The flowers pollinate themselves and then lose their petals as the fertilized ovary begins to enlarge. The budding ovary or “peg” grows down away from the plant, forming a small stem, which extends to the soil. The Peanut embryo is in the tip of the peg, which penetrates the soil. The embryo turns horizontal to the soil surface and begins to mature taking the form of peanut. The plant continues to grow and flower, eventually producing some 40 or more mature pods. From planting to harvesting, the growing cycle takes about four to five months, depending on the type or variety. The peanut is a nitrogen-fixing plant; its roots form modules which absorb nitrogen from the air and provides enrichment and nutrition to the plant and soils.