What is the Difference Between Monocot and Dicot Root

The main difference between monocot and dicot root is that monocot root is fibrous, consists of a wide network of thin roots that originate from the stem, and stay close to the soil surface. In contrast, a dicot root is a taproot having a single, thick root that grows deep into the soil and small lateral branches.

Monocot and dicot roots are the two systems of plants that are primarily underground, taking water and nutrients into the plant body. The root also provides anchorage to the plant.

Key Areas Covered

1. What is Monocot Root
   • Definition, Structure, Function
2. What is Dicot Root
   • Definition, Structure, Function
3. Similarities Between Monocot and Dicot Root
   • Outline of Common Features
4. Difference Between Monocot and Dicot Root
   • Comparison with Key Differences

Key Terms

Dicot Root, Monocot Root, Root

What is Monocot Root

Monocot root is a fibrous root. Generally, roots are covered with root hairs that aid in the absorption of water and nutrients from the soil. Moreover, the outermost layer of the root is the epidermis. Beneath the epidermis, the cortex occurs. In monocots, sclerenchyma cells occur in the cortex while in dicots, parenchyma cells occur in the cortex.

Figure 1: Monocot Root

Furthermore, the endodermis separates the cortex from the stele, the central part of the root. In addition, the xylem and phloem develop in the stele. The pericycle is the outermost layer of the stele. Generally, the pericycle divides and gives rise to lateral roots. Pith occurs in the central part of the monocot root. In monocot roots, the vascular bundle occurs in circular patterns.  

What is Dicot Root

Dicot root is the taproot. The vascular bundle of the dicot root occurs in the middle of the root, surrounding the vascular cambium. In general, the two types of vascular tissue in the plant root are the xylem and phloem. The main function of the xylem is to absorb and carry water from the root to the leaves. On the other hand, phloem carries sugars, organic compounds, and other substances from leaves to stems and roots.

Figure 2: Dicot Root

Furthermore, the monocot root contains more vascular bundles in comparison to the dicot root. In the dicot root, the vascular cambium separates the xylem from the phloem. Here, vascular cambium is the tissue that develops secondary growth in the dicot root. However, monocots do not contain a vascular cambium.

Similarities Between Monocot and Dicot Root

• Monocot and dicot roots are two root systems found in plants.
• Their main function is to absorb water and nutrients from the plant body.
• Moreover, they grow underground.
• They provide support to the plant.
• The main structure of the root contains the root hair, epiblema, cortex, endodermis, phloem, pith, perixylem, and metaxylem.

Difference Between Monocot and Dicot Root

Definition

Monocot root refers to the fibrous or adventitious roots consisting of a wide network of thin roots and root fibers that originate from the stem while dicot root refers to the taproots consisting of a single primary root from which secondary and tertiary roots develop and grow vertically downwards through the soil.

Pericycle

In monocot roots, the pericycle only gives rise to lateral roots, while in dicot roots, the pericycle gives rise to cork cambium, parts of the vascular cambium, and lateral roots.

Vascular tissues

Monocot root contains a higher number of xylem and phloem while dicot root contains a limited number of xylem and phloem.  

Shape of Xylem

Generally, the monocot xylem is round or oval while the dicot xylem is angular or polygonal.  

Number of Xylem and Phloem

Moreover, monocot xylem can be 8 to many in number while dicot xylem is 2 to 8 in number.

Pith

In the monocot root, the pith is large and well-developed, while in the dicot root, the pith is absent.

Conjunctive Tissue

In the monocot root, the conjunctive tissue is sclerenchyma, while in the dicot root, the conjunctive tissue is parenchyma.

Secondary Growth

Secondary growth is absent in the monocot root while secondary growth occurs in the dicot root.

Cambium

The cambium is absent in the monocot root while the cambium is present in the dicot root.

Xylem

The xylem is polyarchy in monocot root while the xylem is tetrarchy in dicot xylem.

Cortex

The cortex is very wide in the monocot root while the cortex is comparatively narrow in the dicot root.

Covering

Exodermis covers the older roots in the monocot root while the cork covers the older roots in the dicot root.

Examples

The roots of maize, banana, and palm are examples of monocot roots while pea, beans peanut roots are examples of dicot roots.

Conclusion

In brief, the monocot root is the fibrous root. It consists of a wide network of thin roots and root fibers that originate from the stem. The dicot root, on the other hand, is the taproots, which consists of a single primary root from which secondary and tertiary roots develop and grow vertically downwards through the soil.  Therefore, the main difference between monocot and dicot roots is their structure.

References:

1. Wikimedia Foundation. (2022, August 7). Root. Wikipedia. Retrieved August 16, 2022.

Image Courtesy:

1. “Prop roots of Maize plant” By Krish Dulal – Own Work (CC BY-SA 3-0) via Commons Wikimedia
2. “Root dicot stems Parenchyma cells” By Naz Amann – Own Work (CC BY 4.0) via Commons Wikimedia