In this article, learn all about plant movement from what plants can move, as well as why they move and how often they move.
You will learn the answer to some of the more conceptual questions about plant movement too, like whether plants have feelings and how they interact with each other chemically.
(I promise, botany makes watching grass grow a lot cooler than it sounds…)
Are There Any Plants That Move?
Yes, there are plants that move. In fact, while not every plant moves in the same way or at the same speed, every plant moves.
There are even a few popular examples of plants that move that you might already be quite familiar with.
These plants include the morning glory with its curling tendrils (Ipomoea purpurea), or the sensitive plant which collapses on itself if touched (Mimosa pudica), or even the ever-famous sunflower which is said to track the sun throughout the day (Helianthus annuus).
How Do Plants Move?
For sessile organisms, plants move a great deal in response to different environmental factors such as temperature, sunlight, gravity, sensation, pests, chemicals; the list goes on.
Plants move just about every part of their anatomy over time:
- Shoots or active growth regions (growing and moving towards the sun)
- Flowers (blooming)
- Roots (growing into soil with gravity, towards nutrients and water)
- Reproductive organs (movement of pollinated tissue to internal ovaries)
- Leaf tissue (in response to touch or electrical stimulation)
- Propulsion of seeds (seed dispersal)
These methods of movement are often too slow for us to sit and watch over time, but careful observation and technological advances – in the case of timelapse photography – has allowed us a remarkable insight into the restless movement of plants everyday.
Can a Plant Walk?
No, plants cannot walk in the traditional sense that we might consider, with conscious movement of one foot in front of the other with the intention of relocating itself.
One plant action that closely resembles this action, however, has been identified by Socratea exorrhiza also known as “The Walking Tree.”
To chase areas of greater sunlight, old roots will die off, and it will regrow roots closer to the sunlight. Between this and its stilted root system, it gives the tree the appearance of legs which walk from one location to another.
Tropisms
Plants have something defined as a -tropism, which is a response to their environment based on certain factors. (1) This is the main mechanism behind any kind of plant movement and is completely reactive to the environmental stimulus.
In an attempt to compensate for their sessile nature, plants have developed growth responses to deal with the copious and rapid changes in their environment.
Below are the primary types of tropisms that occur in plants:
- Phototropism
This type of tropism is a plant’s response to light, either growing towards or away from light.
- Geotropism, or Gravitropism
This is the plant’s response to gravity, either growing away from or with gravity, towards the earth.
- Hydrotropism
The plant’s response to water, either toward or away from moisture.
- Thigmotropism
The plant’s response to touch, either growing towards or away from the source. Vining plants use this to find a structural support to grip onto, the Venus flytrap uses this to snap its trap shut on unsuspecting prey, and the Mimosa pudica will close its leaves once it senses touch to protect its delicate leaves.
- Thermotropism
This is the plant’s response to temperature, growing either towards or away from hot or cold temperatures based on its needs.
- Chemotropism
This is the plant’s response to a particular substance, either towards or away from things like soil, pollutants, and even hormonal changes within the plant.
In root growth, plants may go towards deposits of beneficial nutrients, or away from harmful polluting chemicals. In plant reproduction, pollen tubes may grow and elongate once pollinated to fertilize an internal ovary.
Do Plants Like to Be Moved Around?
There’s a common myth that some houseplants like to be moved around, and this simply isn’t true, just like it’s not true in nature.
Plants release stress signals when they are shaken or moved around and may have a hard time adjusting to a new location if you change where they are located, especially if there’s a difference in humidity, light, or temperature.
Does it benefit your plant to shake it gently or move it around? This is a different distinction, and yes, sometimes plants do benefit from being moved as it causes physiological changes that can strengthen their stems or shoots.
You can absolutely over-do it and cause harmful effects due to the stress responses, however.
For example, for houseplant growers who have a Fiddle Leaf Fig (Ficus lyrata) who are struggling with the plant’s stem leaning or sagging, wiggling the plant can cause it to grow stronger as it recognizes the input and it begins giving more attention to the structure of the stem when building new cells.
This same thing works when you do a lot of core exercises in your regular daily life – your abdominal muscles strengthen as a response because your body recognizes the need to use those muscles. Likewise, in an especially windy environment, trees may grow thicker and shorter to compensate for the constant movement and pressure on their stems; you see this often on wind-blown coastal beaches.
The More Conceptual Side of Movement…
It wouldn’t be HerbSpeak without exploring all sides of plant movement, including the more conceptual.
We know that plants move, and we even know that plants can communicate with each other by releasing chemical and hormonal signals within its stems and even into the air; this is how plants know how to fruit on time, or how they know when to produce more of a pest-resistant compound.
If plants have the power to move and communicate, wouldn’t they have the ability to feel, both in the sensory meaning of the word, as well as the emotional?
Do Plants Scream When You Cut Them?
No. Plants do not scream when you cut them, so you don’t have to feel bad about mowing your lawn. Plants do, however, in many cases release pheromones that tell nearby grass to produce compounds to make themselves unpleasant to potential predators.
This type of communication is not new or novel in plants, though it has widely been misinterpreted as “screaming” which provides an emotional connotation of anguish or pain.
Do Plants Like Music?
This is actually a really rather controversial subject. At the root of it all (heh) plants don’t have the capability to enjoy or dislike something.
Some studies, however, have found that some plants grow better when specific songs are played nearby, while others found no correlation at all between music and growth rate.
It’s not because of the music; plants respond well to vibrations in the air and in the soil. It is suspected that plants respond best to music or sounds that best emulate their natural environment, but once again, there’s no definitive proof of either of these.
But you know what? Play that song for your plant and dote on it, because if it makes you happier, that is a proven benefit.
Do Plants Feel Love?
No. Moving on.
In all seriousness, plants do not have the capacity to feel emotion in this sense because they do not have the consciousness or experiential capabilities to develop emotional bonds.
If you feel a bond with your plant, power to you – but don’t expect it to be more than a one-sided relationship at any point.
Do Plants Have Genders?
Yes, some plants do indeed have genders in a very obscure way, as surprising as that might be. Plants themselves cannot be female or male or both, as that self-identity is not available to them. They can, however, have male or female parts anatomically.
A great example of male and female plants is the Passionflower (Passiflora incarnata) which requires both a female and a male vine to become pollinated and produce fruits. It’s not uncommon for plants to even have both anatomical parts, and some plants can even self-pollinate.
Plants that are either male or female is known as a dioecious plant, while a plant with both parts is known as a monoecious plant.
Concluding Thoughts on Plant Emotion and Sensation
This can be a difficult subject to study because humans are naturally emotional, and we easily develop emotional bonds with whatever we are close to, even plants. This makes it problematic to give a definitive answer and disprove a bias in the researcher themselves.
Objectively, however, there is no evidence that plants can reciprocate those emotional bonds, and while they can feel physical stimulus, and might secret hormonal changes to warn other plants, there is no evidence that they can feel pain.
Unfortunately, anthropomorphism in regular media, with headings like “Plants feel pain too! Researchers find ultrasonic ‘scream’ emitted with stems are cut” or “Plants are smart, and do scream when you cut them” are incredibly misleading.
Pain appears to be a completely separate sensation that is reliant on something called nociceptors, a type of receptor in the skin that is not present in plants but in other organisms like mammals, invertebrates, insects, and others.
Likewise, without a brain, plants would be unable to truly experience the sensation of pain, at least in the same way that we do. This, however, does not make them exempt from being able to sense touch, which is how many “plant music” devices work, by turning those electrical signals from touch into sound waves.
Why Do Plants Move?
Movement is advantageous in being able to respond to the environment in some way, whether by growing in a new direction to acquire more sunlight, or by sinking the roots deeper towards the Earth’s center, or towards the vibrations of a stream of water underground.
Plants are unable to respond to their environment quickly in the same ways or manners that mammals and other organisms might. Various tropisms allow plants to adjust to their environment and improve their likelihood of survival.
References
- University of Missouri-Columbia, Plant tropisms: providing the power of movement to a sessile organism, https://pubmed.ncbi.nlm.nih.gov/16096973/
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