The key difference between rhizoids and rhizomes is that rhizoids are root-like filaments growing out of epidermal cells of bryophytes which are useful in anchoring in place and absorbing nutrients and water while rhizomes are horizontally growing underground modified stems which store foods and are useful in vegetative propagation.
Rhizoids and rhizomes are two root-like structures that function differently. Rhizoids are small root-like filaments which help bryophytes and fungi to attach onto a substrate and absorb nutrients and water. Rhizomes, on the other hand, are root-like modified, underground stems which store foods and are useful in vegetative propagation. Rhizomes are able to give rise to new plants. Rhizomes have internodes, small leaves, buds, and nodes. Moreover, they grow horizontally underground, unlike rhizoids.
CONTENTS
1. Overview and Key Difference
2. What are Rhizoids
3. What are Rhizomes
4. What are the Similarities Between Rhizoids and Rhizomes
5. Side by Side Comparison – Rhizoids vs Rhizomes in Tabular Form
6. Summary
What are Rhizoids?
Rhizoids are hair-like or small thread-like filaments that support bryophytes to attach to a substrate and absorb nutrients and water. Structurally, rhizoids can be either unicellular or multicellular. They grow out of epidermal cells. Bryophytes such as mosses, liverworts and hornworts possess rhizoids. They are nonvascular plants that have no true stems, roots and leaves. Therefore, in bryophytes, rhizoids fulfil the same function as true root hairs of vascular plants.
Figure 01: Rhizoids
Fungi also have rhizoids which are branching downwards from hyphae. Fungal rhizoids help to anchor thallus into growth surface and absorb nutrients. In addition to bryophytes and fungi, certain algae also have rhizoids. Algal rhizoids aid them to anchor themselves to a sandy substrate and uptake nutrients.
What are Rhizomes?
Rhizomes are root-like stems which are parts of the main stem. They grow horizontally or in other direction inside the soil. This underground plant stems have nodes, and from those nodes, new roots and shoots originate. Rhizome is a useful part of vegetative propagation. It can give rise to a new plant. Structurally, rhizomes are thick and short. They are similar to stolons. They grow slowly.
Figure 02: Rhizome
Rhizomes store starch and proteins. They also enable plants to survive underground in unfavourable conditions. In ferns, rhizomes are a notable adaptation which allows new frond development. Moreover, rhizomes of some species are edible, and they are used in cooking. For example, ginger is an underground rhizome which is used as a spice and condiment. Rhizomes of turmeric have a wide range of food and pharmacological applications. Moreover, rhizomes of galangal, fingerroot and lotus are also used in cooking directly. Rhizomes can also be seen in plants such as iris, canna lily, Chinese lantern, poison-oak, bamboo, bermudagrass and purple nut sledge, etc.
What are the Similarities Between Rhizoids and Rhizomes?
- Both rhizoids and rhizomes are root-like structures.
- They are mostly underground structures.
- Nonvascular plants have rhizoids while higher plants have rhizomes.
What is the Difference Between Rhizoids and Rhizomes?
Rhizoids are simple hair-like filaments that support bryophytes to attach onto a substrate and absorb nutrients and water. Rhizomes are underground modified stems that are specialized to store foods. So, this is the key difference between rhizoids and rhizomes. Furthermore, rhizoids behave as roots of higher plants in anchoring and absorbing nutrients while rhizomes behave as stems giving rise to new roots and shoots.
Moreover, rhizoids are not useful in vegetative propagation while rhizomes are very useful in vegetative propagation. Thus, this is another significant difference between rhizoids and rhizomes. Besides, rhizoids are not able to store foods while rhizomes are able to store food.
Below infographic tabulates the differences between rhizoids and rhizomes for side by side comparison.
Summary – Rhizoids vs Rhizomes
Rhizoids are thin hair-like structures that help bryophytes to attach onto a surface and absorb nutrients and water. Rhizomes are modified stems that store food. Rhizomes can give rise to new shoots and roots. Rhizoids function as roots of higher plants while rhizomes function as stems of higher plants. Rhizomes are used in vegetative propagation. Thus, this is the summary of the difference between rhizoids and rhizomes.
Reference:
1. “Rhizome – Definition and Examples – Biology Online Dictionary.” Biology Articles, Tutorials & Dictionary Online, 26 Nov. 2020, Available here.
2. “Rhizoid.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., Available here.
Image Courtesy:
1. “Riccia Rhizoide 050910” By BerndH – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Curcuma longa roots” By Simon A. Eugster – Own work (CC BY-SA 3.0) via Commons Wikimedia
Leave a Reply