Parts of a Peanut Plant – A Guide to the Anatomy and Growth Stages

The peanut, or Arachis hypogaea, is a special kind of legume that is used in many different ways in cooking around the world. Understanding the anatomy and functions of the peanut plant is crucial for agriculturalists, botanists, and food scientists alike. This article talks about the different parts of the peanut plant and explains what they do and how important they are to the plant’s life cycle and productivity.

The peanut plant has unique growth habits that differ from most other crops, Its flowers form above ground while the fruit develops underground Understanding the various parts of the peanut plant and its stages of development can help farmers and gardeners provide proper care for a healthy harvest,

In this guide. we will cover

  • The major structures and functions of peanut plant parts

  • The life cycle and growth timeline of a peanut plant

  • Key steps in the peanut growth process

  • How peanuts develop and mature underground

Main Parts and Functions

The main structures of the peanut plant include:

  • Leaves: Oval-shaped alternate leaves up to 12 inches long convert sunlight into food via photosynthesis.

  • Stems: Primary stems grow erect up to 18 inches tall. Lateral branches trail along the ground up to 6 feet.

  • Flowers: Small yellow flowers with red veining form at the base of leaves. Peanut flowers self-pollinate.

  • Roots: A central taproot anchors the plant while lateral roots form nodules that fix nitrogen.

  • Pods and Seeds: The ovary of the flower stretches into a pod containing 1-4 seeds (peanuts) that develops underground.

The Peanut Plant Life Cycle

Peanuts are annual plants with a 4-5 month growing time from planting to harvest. Here are the key stages:

1. Germination

Seeds are sown 1-2 inches deep in soil. They absorb water and sprout in 5-10 days.

2. Emergence

Seedlings emerge above ground about 2 weeks after planting. Stems and leaves grow rapidly.

3. Flowering

Flowers appear at the lower portion of the main and lateral stems around 4 weeks after emergence.

4. Pegging & Pod Development

Flowers pollinate themselves, then the fertilized ovary extends into a stem-like “peg” that grows down into the soil. There, the peg tip enlarges into the peanut pod and seeds. Pods reach full size in about 2 months.

5. Maturation

Inside the pods, peanuts grow to maturity. Their green inner shell changes to a brown seed coat.

6. Harvest

After 4-5 months, mature peanut plants are dug up and pods are removed for drying and curing. Plants are then incorporated back into the soil.

Underground Pod Development

One of the most unique aspects of the peanut plant is its unusual underground fruit formation. Here’s how it happens:

  • After self-pollination, the flower’s ovary lengthens into a narrow “peg” that extends down towards the ground.

  • The peg grows 2-6 inches long, then burrows horizontally into the soil.

  • The tip of the peg begins swelling into the peanut pod shell that contains 1-4 seeds (peanuts).

  • The pods rapidly expand to full size underground in about 60 days after flowering.

  • Inside the shells, the peanuts continue maturing and growing to fill the pods.

This unusual process means peanut flowers above ground end up producing the edible seeds below ground. Understanding the parts of the peanut plant helps growers ensure pods can properly penetrate the soil and expand underground. With the right conditions, those tiny flowers give way to a bountiful peanut harvest.

Flowers: The Beginning of Reproduction

Peanut flowers are bright yellow and typically self-pollinating. Once the flower is pollinated, an interesting process called geocarpy starts. The ovary of the flower gets longer and shapes into a peg that digs into the ground, where the peanut will grow.

  • Self-pollination: Flowers contain both male and female parts, promoting self-fertilization.
  • Geocarpy: The unique reproductive strategy where the fruit develops underground.
  • The flower has a calyx, stamens, a pistil, and a corolla.

Root System: The Foundation of Nutrient Uptake

The peanut plant’s roots are fibrous, made up of a bunch of thin roots that spread out in the ground. This network is essential for anchoring the plant and absorbing water and nutrients. Nitrogen-fixing bacteria live in the roots and change nitrogen in the air into a form that plants can use. This also makes the soil better.

  • Nodulation: Root nodules house symbiotic bacteria that fix nitrogen.
  • Absorption of water: Small root hairs make the surface area for taking in water bigger.
  • Nutrient uptake: Roots absorb essential minerals like phosphorus and potassium.

How do peanuts grow? | Natural History Museum

FAQ

What are the parts of a peanut plant?

The peanut seed consists of two cotyledons (also called seed leaves) and an embryo. The embryo comprises the plumule, hypocotyl and primary root. The plumule eventually becomes the stems and leaves of the plant, and the hypocotyl is the white, fleshy stem located between the cotyledons and the primary root.

What is the stem of a peanut plant called?

The flowers bloom for only about half a day; the blossoms are self- pollinating. About 4 days later, a stem (also called a peg) will grow from the flower and head into the soil. At the end of each stem, the seedpods (peanuts in the shell) will grow.

What is a peg on a peanut plant?

Peanut has a unique mechanism to embed fertilized ovary of flower into the ground through specialized organ known as the peg or gynophore. Peg is a tube like structure which is formed after successful fertilization in flowers.

What is a peg in a peanut plant?

“Pegging” is a Unique Feature. This budding ovary is called a “peg.” The peg enlarges and grows down and 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 a peanut.

What makes a peanut plant unique?

The peanut plant is unique because its flowers grow aboveground, yet the pods containing the seeds develop in the soil. The yellow, pea-like blossoms are self-pollinating. Once fertilized, the delicate petals fall away. The stalks (pegs) just under the ovaries then elongate and bend toward the earth, growing into the soil.

How to plant peanuts in a container?

If you want to plant peanuts in a container, you must use self-draining planters with the specifications mentioned earlier. Fill the planters 2/3 to 3/4 full with pre-moistened potting soil to give the roots enough room to grow. Dig a hole where you can place the peanuts and then cover them completely with soil.

Do Peanuts grow on trees?

Many people are surprised to learn that peanuts grow beneath the soil and do not grow on trees like pecans or walnuts. Below you’ll discover how peanuts grow, from preparing the soil for planting to the peanut harvesting process. First, Farmers Plant the Seeds.

Leave a Comment