Photo courtesy of vinod velayudhan via Flickr. Modified by Curiousmatic.

Humans can’t telepathically communicate, produce chemicals to protect themselves and others from diseases, or lure animals by scent alone. Plants, on the other hand, can do all of these things — and more.

What many people don’t realize is that plants communicate (soundlessly) between one another – as well as with other plants, insects, and even animals, all the time. For brainless organisms, our green friends certainly have some interesting abilities.

Scientists have been learning more and more about what they say, and how. Their findings may surprise you.

Plants talk to everyone (except humans)

The website Psychobotany references a since-refuted 1966 experiment by former CIA agent Cleve Backster, which concluded plants could sense and respond to human thoughts and threats.

Plants, however, lack the nervous and sensory organs animals have to think and feel, rendering claims like this scientifically incredible.

But there are other levels of plant-life intelligence that fit better into the anatomy and functionality of plant life. They may not respond to the thoughts and threats of humans, but they do communicate with microorganisms, fungi, insects and other animals, other plant species, and between cells of a singular plant.

Like a good neighbor, telepathy is there

According to a study published in BMC Ecology, infinitesimal vibrations called “nanomechanical oscillations” pass inaudible sound waves between plants. The signaling causes plants such as pepper seeds to grow better when near “good neighbors” like basil than alone – even when plastic separates the two.

Adversely, bad neighbors hinder plant growth. Feuding plants chili and fennel experience negative germination in close contact, even when all known channels of communication are shut off between them (light, chemical, and touch).

Fungal connections and scented motivations

A study published in Ecology Letters demonstrates how underground networks of fungi called mycorrhizae are utilized to warn other plants of attack, causing them to produce defensive chemicals to warn off predators or pests.

According to a paper on plant signal communication, plants such as lima beans have up to five different defense strategies against infestation, which they enact by exuding a repellent scent to not only lima beans, but (quite generously) other surrounding plants.

Some plants communicate with animals for their own purposes, as well. One study found that a plant called Cytinus visseri uses a unique combination of chemical scents to lure mammals that will aid them in pollination. Which serves to make one wonder if flowers are just plants’ way of manipulating love-struck humans to spread their seeds, too.

Intelligent response to light, time, and sound

Plants may not have brains, but they are certainly perceptive. Plants such as corn stalks emit sounds at high frequency, and were found to grow toward sources of similar sounds, even artificial ones. Plants also associate wavelengths of light with danger, which they are capable of remembering, and have proteins that measure time by light to know when to bloom.

All of this to say that, if a tree falls in a forest and no one is listening, its communication level may still be up for debate. Perhaps the reason no one’s heard it yet is that we don’t speak their language, despite the remarkable things they say.