The main difference between the stem tuber and the root tuber is that the stem tuber is a swollen stem while the root tuber is a swollen root. For example, potatoes are stem tubers while dahlias are root tubers.

Stem tuber and root tuber are two types of tubers that are swollen from storage of water and nutrients. Compared to other geophytes such as onions, tubers or rhizomes , tubers do not produce any offset, but rather grow from year to year.

Key areas covered

1. What is a tuber - definition, facts, examples 2. What is a tuber - definition, facts, examples 3. What are the similarities between tuber and tuber - overview of the common characteristics 4. What is the difference between tuber and tuber - Comparison of the main differences

key terms

Chlorophyll, eyes, root tuber, stem tuber, underground swollen structures

What is a stem tuber?

Stem tuber is a swollen stem that stores water and nutrients. These nutrients and water are used in adverse conditions such as drought or winter months. Stem tubers generally form near the surface of the soil. You have several nodes called eyes that develop into new plants. Also, stem tubers produce chlorophyll when exposed to sunlight.

Figure 1: Potatoes

What is a tuber?

Root tubers are the roots that are swollen from storage of water and nutrients. They are also called root crops . Root tubers perform the general functions of roots such as absorbing water and minerals and anchoring the plant body in the soil. Some examples of tubers are beets, carrots, parsnips, and dahlias.

Figure 2: Carrots

Carrot has an enlarged tap root. Some tubers are formed from adventitious roots.

Similarities between the stem tuber and the root tuber

• Stem tuber and root tuber are two types of geophytes.
• Both are underground swollen plant structures.
• They store water and nutrients.
• They anchor plant bodies in the ground.

Difference between stem tuber and root tuber

definition

Stem tuber refers to a short fleshy, usually subterranean stem that bears tiny scale leaves, each of which has a bud in its axilla and may be able to produce a new plant, while root tubers refer to a tuber root or storage root, one modified lateral one is the root, enlarged to function as a storage organ.

Type of tuber

Root tuber is a swollen stem, while root tuber is a swollen root.

storage

The stem tuber can store more starch , while the root tuber can store comparatively less starch.

Carbohydrate composition

Root tubers mainly store complex carbohydrates like starch, while root tubers store simple carbohydrates like glucose .

Number of tubers

There are several stem tubers per plant, while there is only one tuber per plant.

Apical bud

Stem tubers have an apical bud at the tip, while root tubers do not have an apical bud.

Development of chlorophyll

Stem tubers develop in sunlight chlorophyll , while tubers may develop chlorophyll.

Scaly leaves and auxiliary buds

Stem tubers have scaly leaves and auxiliary buds, while root tubers do not have scaly leaves and auxiliary buds.

root

Stem tubers have no roots, while root tubers have some fine roots.

Create new plants

Any part of the stem tuber can grow into a new plant if the tuber is cut into pieces, while the parts of a root tuber cannot develop into new plants.

Examples

Potatoes are stem tubers, while beets, carrots, parsnips, and dahlias are root tubers.

diploma

Stem tubers are the swollen stems, while root tubers are swollen roots. Stem tubers have multiple eyes that develop into new plants. The main difference between stem and root tuber is the part of the plant that swells.

Reference:

1. "Bulb". Wikipedia , Wikimedia Foundation, July 10, 2018, available here

Image courtesy:

1. "Food-Root-Nature-3291163" ( CC0 ) via Max Pixel 2. "Carrots" according to the color line ( CC BY 2.0 ) via Flickr