Plants are vital life forms, and they are a source of food, shelter, and nutrition, and they aid in balancing the oxygen level in the atmosphere.
The root is an important part of a plant, usually located below the ground; plants have different types of roots.
They perform several functions such as holding the plant in the ground, conveying nutrients from the soil to the rest of the plants, absorbing water, and storing reserve foods.
However, not all the types of roots in plants are underground; some roots grow above the ground. They are termed aerial roots; just like the underground roots, they are also responsible for absorbing nutrients and anchoring the plants.
The types of roots in plants are peculiar to the specie of plant.
Parts of the roots in plants
Root cap
The tip of a root is usually tender; the thimble-like root cap protects this tender part and helps it extend deeper into the soil. The root cap produces mucilage responsible for making it easy for the passage of the root through the soil.
The meristematic region
This term means rapid growth. This region is found slightly above the root cap; the region contains cells that grow rapidly. The cells are very small and thin-walled with dense protoplasm.
The region of elongation
The cells found in this region are responsible for the increase in root length. The cells here would normally enlarge and elongate.
The region of maturation
After cells enlarge and elongate, they mature due to differentiation and form the maturation region. This region is made up of specialized tissues like root hairs.
Types of Roots in Plants
Here is a list of the types of the root system and types of roots in plants; The roots of a monocotyledon are called monocot roots.
The monocotyledon plants are recognized to have a single cotyledon in their embryo. The monocot root contains multiple xylem and phloem; the xylem and phloem are arranged in a circular order.
The pith is fully developed, and the pericycle produces lateral roots only. The roots of a dicotyledon are called dicot roots.
They have two cotyledons in their embryo. In a dicot root, the xylem and phloem are limited; the xylem is usually located in the middle, with the phloem surrounding it.
The pericycle of a dicot root gives rise to various lateral roots, cork cambium, and vascular cambium. Although secondary growth does not occur in the monocot roots, they happen in the dicot roots.
The types of roots in plants include;
1. Taproots
The taproot is usually thick; it is a single primary root that grows downwards into the soil. Other roots (secondary and tertiary roots) sprout from the primary root.
The taproot provides strong anchorage due to how deep they penetrate the soil. The other roots that grow off the main root have an acropetal succession.
This refers to the arrangement of branches, where the older branches are present at the base, and younger branches are present at the apex.
The taproots of some plants do not grow deep, but rather, the lateral roots grow horizontally along the surface. These roots are called feeder roots.
Characteristics;
- They develop from the radical of an embryo
- They grow under the surface of the soil
- They have a primary root with branches that grow off it
- They usually penetrate deep into the soil; that is, they act as deep feeders
- The main root remains throughout the plant’s life
2. Fibrous roots
Fibrous roots are mostly found in monocot plants, and the roots are branched and grow directly from the stem. The roots do not provide anchorage because they lack depth in the soil; they grow close to the surface and spread horizontally.
The primary root is short-lived due to the numerous roots of the fibrous system replacing the primary root.
Characteristics;
- They grow underground
- They have a cluster-like appearance with numerous roots of almost the same size
- The primary root is short-lived
- They do not penetrate deep into the soil
3. Adventitious roots
They are like the fibrous roots, but they do not grow directly from the radical, and they grow from the leaves, stem nodes, and inter-modal parts of the plant.
According to the species, these roots can be underground or aerial, thick or thin. They grow under stress conditions such as plant injury and water-logging after floods, increasing a plant’s survival chances.
4. Tuberous roots
These roots are very thick, fleshy, and enlarged. They serve as storage organs that store a reasonable amount of food for the whole plant. They are modified from the plant stem.
5. Creeping roots
Creeping roots do not penetrate deep either; they are usually shallow and spread horizontally from the base of the plants. They often grow as long vines and are used as ground covers. They cover large areas; many trees have creeping roots.
6. Water roots
Plants in water grow water roots. They can use oxygen from the atmosphere for growth and metabolism. They are also morphologically different from the soil roots.
Many herbs are easily rooted in water, for example, baby bears, impatiens, grape ivy, Christmas cactus, fiddle leaf fig, Swedish ivy, etc.
7. Parasite roots
As the name implies, parasite roots depend totally and derive their nutrients from other plants. The roots of the plants that the host tissues absorb nutrients are called haustorial roots, and they are not beneficial to the host plant and usually cause serious damage to the host plants.
Functions of Roots in Plants
The root system is a fundamental part of plants, and their functions are vital for the growth and survival of plants.
The different types of roots in plants have the same functions; anchorage, absorption, storage, and ecological function.
- For anchoring: the root supports the plant body and ensures that the plant remains on the ground. Plants can stand firm for years because their roots deepen in the soil.
- For absorption: the root absorbs water and nourishment from the soil through the root hairs. The nutrients they absorb are essential for their growth; they move upward to the stem and leaves after they are absorbed. The absorption and conduction of these nutrients are necessary for photosynthesis. Plants prepare their food through photosynthesis.
- For storage: plants store food in leaves, shoots, and roots in starch form. Examples include beetroot, cassava, carrot, yam, radish, etc.
- For ecological function: they provide habitat for some organisms, prevent erosion, provide sustenance for living things, and eventually progress the economy.
The types of roots in plants each have their unique features and characteristics but the same functions, built for the same reasons.
