In most plants, but not all, the roots are the part of the plant that is below the surface of the ground. In the case of hydroponically grown plants, the roots are below the surface of the water. Some roots grow above the ground and some poke up into the air from the ground.
Roots play two very critical roles in plants. Roots provide an anchor for the plant, keeping them upright and enabling plants to grow tall and wide. The second, and even more important function, is the absorption of nutrients and water from the ground. In addition to absorbing nutrients, roots also act as food storage containers.
Types of Roots
Below are all the different types of root structures found in plants with a brief description of the type. In time we will expand this section and go into more detail about plant roots.
Roots that develop from any part of the plant other than the radicle are considered adventitious. The most common place for these types of roots to develop are other old roots, but they can also grow out from stems and leaves.
Quite simply, aerial roots are above ground growing roots. Aerial roots are found in several different types of plants. Some examples of plants with aerial roots are poison ivy, mangrove trees, and orchids.
A fibrous root system consists of very thin roots branching out from the stem. As mentioned, these roots are thin, but are usually very strong. Common weeds are a good example of a plant with a fibrous root system.
Roots that are larger in diameter and soft to the touch are called fleshy roots. Fleshy roots normally store more nutrients for the plant than other root types.
Plants with haustorial roots tend to suck the life out of plants around them. Haustorial roots spread out to invade other plants' root system and depletes them of nutrients.
The primary root is also called the radicle. The primary root is the first root to emerge from the seed during germination.
As you can imagine, secondary roots grow off of the radicle, or primary root (see above). Secondary roots are also often called branch roots.
A taproot is a primary root (see above) that grows downward into the ground, and tapers as it gets deeper. As the main root, it creates a central root from which others can grow. Examples of plants with a taproot are dandelions, radishes and carrots.
Tuberous roots are thick, soft and usually more round
in shape than long. They contain more storage tissue
than most roots. Sweet potatoes are prime examples of
plants with tuberous roots.