Nastias: what they are and examples - Summary

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At Ecologist Verde we want to teach you a little more about the world of plants and, above all, how they relate to the environment. In this article we will answer the question about whether the plants move or not and we already clarify that, yes they do. In fact, they only make movements in response to a foreign or external stimulus and are known as nastias. In this article we will talk about what are the nastias of plants and examples of these, so some of the characteristics of the nastias will also be indicated. Keep reading to expand your knowledge of botany and so that, in addition, this helps you to value the environment even more.

What are nastias

The temporary movement that can occur in the different organs that make up the plant and that are produced by an external stimulus is called nastia. Therefore, we can say that the definition of nastias can be summarized in that movement that occurs in response to an external stimulus and that, therefore, does not have to be directly related to its growth. We should also point out that the term "nastias" comes from "nastos" which means in Greek to squeeze or close with pressure. Hence, many of them are related to the opening and closing of the flowers or the expansion of the leaves in search of sunlight.

But what function do nastias fulfill? The answer is simple: nastia are necessary for the plant to be able to adapt to different external agents to protect and strengthen itself in search of optimal growth.

Examples of nastias

The best way to understand what and how are the movements of the plants that define the nastias is, simply, to know how the nastias are classified. Within this classification we will find examples of plants with nastias, such as carnivorous plants or mimosa.


As its name indicates, this type of nastia occurs as a response of the plant itself to light intensity. A clear example is how flowers open or close depending on sunlight. Starting from this base, we can understand that there are, therefore, positive and negative nastias. Sunflowers perform a positive photonasty by looking down when the sunlight disappears, while the morning glory, which opens its flowers in the dark, performs a negative photonasty.

Chemo nastia

Carnivorous plants when trapping insects perform this type of nastia. That which derives from a stimulus produced by a chemical support.


As its name indicates, this type of nastia is a movement produced as a consequence of the damage that the plant itself has suffered. We recommend you read this other post about the question: Do plants feel pain?


This is one of the characteristic nastia types of plants such as mimosa pudica. This nastia occurs due to a stimulus of a mechanical nature or produced by contact that is made immediately and visibly when the leaflets of the plant close.


As with photonastia, we find positive and negative severities. Gravinastia is a temporary and reversible movement that occurs in some plants in response to the action of gravity. An example of positive gravity is when the plant's leaves move downward in response to the earth's own gravitational pull. And negative when the movement is increasing and always in the opposite direction the action of gravity. They are also known as geonastias.


It is the movement carried out as a response of the plants to the presence of humidity in the environment. Ferns show a clear example of this type of nastia when their sporangia open.


It is the movement that occurs in response to thermal variation. Hence, many flowers close or open in response. A clear example is the tulip.


This type of nastia is related to the movement that occurs under the stimulus of the variation between night and day. A clear example is the response of legumes to sunlight, expanding and how they fold during their absence.

Differences and similarities between tropisms and nastias

To finish, we will tell you the relationship and the difference between nastias and tropisms.

Differences between tropisms and nastias

Tropisms are movements of plants that occur in response to an external stimulus and that are carried out in a single direction and permanently. This is achieved thanks to the growth of the plant. However, in the case of nastias, we speak of rapid and reversible movements as a response to an external stimulus that has no influence on the direction in which the movement occurs or where it comes from.

For this reason, it also differs in time and speed of movement. Tropism is a movement that is prolonged in time and is performed slowly, while nastias are sudden movements that are maintained for much less time.

In the same way, tropisms are an irreversible movement, speaking of a movement carried out in response to the action of the growth of the plant, so it is not possible to return to the previous point, while nastias are temporary and reversible movements before the action of an external factor.

Similarities between tropisms and nastias

What nastias and tropism have in common is that they are both movements made by the different organs of plants as a result of an external agent.

Learn more about Tropism: what it is, types and examples with this other article. We also recommend reading this other post about How plants communicate.

If you want to read more articles similar to Nastias: what they are and examples, we recommend that you enter our Biology category.

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