| Root is one of the three main organs of a plant. The others are the stem and the leaf. Most roots are long and round and grow underground. They anchor the plant in the soil. They also absorb water and minerals that the plant needs to grow. In addition, many roots store food for later use by the plant. Plants with roots include all seed-producing plants and most spore-producing plants, such as ferns and horsetails. Liverworts, hornworts, and mosses do not have true roots.
Kinds of roots
The first root to develop from a seed is the primary root. It produces many branches called secondary roots. The secondary roots produce branches of their own.
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There are two main kinds of root systems, taproot or fibrous. In a taproot system, the primary root grows straight down and is called the taproot. The taproot remains larger than any of the secondary roots throughout the life of the plant. In some plants, including beets and carrots, the taproot becomes fleshy (swollen).
Grass is an example of a plant with a fibrous root system. In such a system, the primary root does not remain larger than the others. Many slender secondary roots grow out in all directions. A fibrous root system may become very extensive.
For example, the roots of a rye plant may have a combined length of about 380 miles (612 kilometers). Some plants have modified roots that perform special functions. Roots that grow from the primary root or its branches are called adventitious roots. They include the prop roots of corn and certain other plants.
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Prop roots grow down into the soil from the lower part of the stem and help brace the plant against the wind. Some species of orchids and other plants that live on tree branches send out aerial roots, which cling to the branches. Aerial roots absorb water and minerals from the surface of the tree and from the air. Mistletoe is one of the few plants with roots that penetrate the limbs of a tree. These roots, called sinkers, absorb food, water, and minerals directly from the tree. Kinds of Roots >>> | Parts of Roots >>> | The Importance of Roots >>>
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