- What are the types of roots?
- - Roots according to their shape
- Axonomorphic root
- Fasciculate root
- Napiform root
- Branched root
- Tuberous root
- - Roots according to the direction in which it grows
- Adventitious root
- Fibrous roots
- Foliar roots
- True adventitious roots
- Aquatic root
- Sucking root
- Aerial root
- Storage root
- - Roots according to the support they provide to the plant
- Contractile root
- Stilts
- Epiphytic root
- Male root
- Root systems
- References
There are several types of plant roots, the characteristics of which depend on the plant class to which they belong and the environment in which they develop. The roots are the first parts of the plant to be born and have two main functions: to fix the plant to the ground, and to channel water and nutrients from the ground to the stem and to the rest of the plant, to contribute to its growth and development..
However, there are certain types of roots that are adapted to fulfill secondary functions, such as storage of nutrients and physiological activities other than absorption.
A root is characterized by being cylindrical; It is also geotropic, because it grows towards the ground; and it is positively hydrotropic, because it grows towards the water source.
The roots are also considered negatively phototropic, because they grow in the opposite direction of sunlight. The latter affects that they do not have chlorophyll, so their color is not green.
The root is present in almost all vascular plants and is composed of 5 parts:
- Caliptra
- Epidermis
- Cortex
- Endodermis
- Vascular cylinder
What are the types of roots?
Although those mentioned above are the general characteristics and functions of the roots, there is some differentiation between them, namely:
- Roots according to their shape
Axonomorphic root
It is a thick root from which thinner ones emerge or are born.
Fasciculate root
In this case, it is a branching of roots of the same thickness.
Napiform root
It is one of those roots that fulfill secondary functions, since it has a thicker main root, in which reserve substances are stored.
Branched root
It is a root that resembles a tree, but does not technically have a taproot.
Tuberous root
Although its structure is fasciculate, it is identified because it widens much more when it accumulates enough reserve substances.
- Roots according to the direction in which it grows
Adventitious root
It is the type of root that climbing plants or vines have, which spread over the surface of the soil.
Adventitious roots, in turn, are subdivided into:
Fibrous roots
They resemble threads that grow at the base of the stem, as is the case with those of wheat or onion plants. These threads can also grow at the nodes of a horizontal stem, such as what you see in grass.
Foliar roots
They arise from the petiole or appendage of the leaf, from which it joins the stem. It can arise as a result of an injury or due to the application of hormones.
True adventitious roots
They grow from the nodes and internodes of the plant stem. This is the case of stilt roots in sugar cane.
Aquatic root
As the name implies, they are the roots of plants that grow in aquatic environments. These roots float in the water without any fixing mechanism.
Sucking root
It is the type of root that is introduced into the stem or branch of a plant to extract from it the nutrients that sustain the life of a second, belonging to the species of parasitic plants.
Aerial root
They extend to the ground to support or support a plant that will eventually strangle its host tree.
Storage root
Tubers such as carrots and beets fall into this category, which grow underground as a defense mechanism against herbivorous animals.
These are roots that have evolved for the storage of starch and water.
- Roots according to the support they provide to the plant
Contractile root
They are adventitious roots. They are usually long and fleshy.
They are responsible for dragging the sprout of the plant to a point close to the surface of the soil, so that the development of the sprout is possible.
After three years, these roots contract 40% because their reserves are consumed.
Stilts
They are the roots that grow at the base of the stem, from where they extend to the ground.
They support high-rise trees that lack stability because they grow in shallow soils.
Epiphytic root
They are aerial roots that allow one plant to grow in another without being parasitic. Over time, they join other roots to form something similar to a trunk.
Male root
They grow from the radicle as a taproot. In dicotyledonous plants, this root produces lateral roots that are located in an acropetal succession, which means that the oldest roots are at the base while the youngest are near the apex.
Root systems
Just as there are well differentiated roots, there are roots that function as a system. The main types of root systems are:
- Tap root system, present in plants in dry environments.
- Adventitious root system, typical of plants that spread on a surface, or that come to climb.
There are also aeration roots, like those of mangroves; and haustoric, which correspond to parasitic plants.
Likewise, there are roots that contain nodules in which there are special fungi that contribute to certain types of plants being able to consume nitrogen; and there are plants without any type of root, such as utricularia.
References
- Encyclopedia of Classifications (2017). "Types of roots" in Types of. Recovered from Types of: typesde.org
- Backyard nature (s / f). "Root types" in Backyard nature. Recovered from Backyard nature: backyardnature.net
- Biology (s / f). "Organization of the plant body" in Biology. Recovered from Biology: biología.edu.ar
- Biology discussion (s / f). "Root: characteristics, types, structure and functions" in Biology discussion. Recovered from Biology discussion: biologydiscussion.com
- Botanical (2002). "Types of roots" in Botanical. Recovered from Botanical: botanical-online.com.