Difference Between Rhizome and Tuber

Bookmark added to your notes.
View Notes
×

Rhizome and Tuber are both modified stems of a plant and store food but they are both different from each other in many ways. The experts at Vedantu have created a summary of the difference between rhizome and tuber for the students of Biology. Let’s look in detail at these two parts of the plant first.


Rhizome

Rhizomes are underground and horizontal stems that have fleshy, non-green, and distinct nodes and internodes. Rhizomes resemble the root of a plant. They are brownish because they are away from the sunlight. Rhizomes have terminal buds and they run parallel to the ground. New plants can sprout from the buds on a rhizome. They are also known as root stalks and the rhizome rootstalk grows vertically upwards. Some common examples of  rhizomes are ginger and Alocasia indica

 

Tubers 

Although ‘tuber ‘ is a term that generally denotes any fleshy part but in this case, tubers are the fleshy stem of the plant that stores food. In other words, they are the underground part of the branches that become swollen because of the food that gets stored in them. Unlike rhizomes, tubers grow vertically underground. One of the most common examples of a tuber is a potato that is also used as food. Tubers have several depressions called the eyes and they act as nodes for the tuber. Most tubers are spherical, oval, or oblong. 

 

Let’s see some of the other points of difference between tuber and rhizome.

 

Criteria

Rhizome

Tuber

Stem

Rhizomes are the thick underground stems of a plant

Tubers are the modified stems of a plant and are starchy from inside

Roots

Grow horizontally, parallel to the ground inside the soil

Fleshy roots. They do not grow horizontally.

Thickness

They are less stout than tubers

Most tubers are thick, oval, or oblong

Starch content

Rhizomes have a comparatively lower starch content

Tubers have a high starch content

Part of the plant

Rhizomes are the underground stem of a plant

Tubers are the underground branches of the stem or the underground root

Classification

Rhizomes are not classified into any specific types

Tubers are classified into two types: stem tubers and root tubers

Size

They are smaller in size than tubers

They are bigger than rhizomes

Offspring

New plants can grow from rhizomes and they can produce an offspring

Tubers grow in size year by year

Roots on nodes

The nodes bear adventitious roots on the lower side

The nodes on tubers do not bear roots

Buds

Buds are present in the axils of their scaly leaves and also in the form of terminal buds.

Buds of tubers are known as ‘eyes’ and are present on the surface. 

Examples

Some common examples of rhizomes are bamboo, asparagus, Chinese lantern, the Venus flytrap, ginger, turmeric, Lotus, Western poison-oak, etc.

Some common examples of tubers are begonia, dahlia, carrot, potato, sweet potatoes, yams, anemones,  cassava, oxalis, etc.

FAQ (Frequently Asked Questions)

Q1. How Does a Rhizome Grow into a New Plant?

Ans. Rhizomes are the thick underground stems of a plant. They grow horizontally and parallel to the ground. They have short internodes and roots growing from the bottom of the nodes. This generates new shoots that grow upwards from the top of the nodes. When a rhizome is separated from the plant, each piece can grow into a new plant. A rhizome is used to store proteins, starches, and other nutrients by the plant. When new shoots are formed or the parent plant dies in winters, these nutrients become useful for the plant. This process is known as vegetative reproduction and is another way for rhizomes to produce offspring.

Q2. What are the Two Types of Tubers?

Ans. Tubers are classified into two types: stem tuber and root tuber. Root tuber is a modified lateral root, that functions as a food storage unit for the plant. The storage root which is the enlarged area of the root-tuber is produced at the end or middle of a root. Sometimes it is an entirely new root.  A root tuber is similar in function and appearance to a stem tuber but different in its origin. Some common examples of plants with tuberous roots are cassava, sweet potato, and dahlia.  

 

Stem tubers are formed from thickened stolons or rhizomes. They are formed at the sides of the parent plant and are located near the surface of the soil. The underground stem tuber stores food for a short time and develops from a shoot branching from a mature plant. Some common examples of stem tubers are yams, tuberous begonia, and cyclamens. 

Q3. What are Some Common Examples of Rhizome and Tuber that are Used as Food?

Ans. Some common examples of rhizome used as food are ginger and turmeric and some common examples of tuber used as food like yams, sweet potatoes, and potatoes.