Plants are more aware than we think

            It has taken a long time, but scientists are finally coming to the realization that humans aren’t as unique and superior as was once thought. Yes, our big brains make us the most intelligent creatures around, but we’re not the only animals to use tools, communicate complex ideas, solve problems, make conscious decisions, or even show emotion.

            But what about plants? The blooming daffodils and spring ephemerals that are blooming this month have got me thinking about what talents plants may possess that few of us recognize. They don’t have a brain, so they cannot think, and yet many plants exhibit remarkable abilities to sense and react to the world around them.

            We know, for example, that plants don’t have ears, but that doesn’t mean they can’t hear – which may be a comfort to those who talk to their plants or play the radio all day to keep them

Cartoon by David Chatowsky

entertained. In one study, scientists played a recording of a caterpillar eating leaves, and nearby plants responded by secreting chemicals they use as a defense against caterpillars. There were no caterpillars present, just the sound of caterpillars eating, so clearly the plants could hear it.

            Similarly, Australian researchers played the sound of water trickling through a pipe, and the roots of nearby plants grew toward the sound of the water. Again, no actual water was trickling, and yet the plants detected the sound, recognized it was a useful resource, and reacted appropriately by extending their roots toward the faux water.

            Hearing is only one of the many senses that plants exhibit. Some researchers claim that they may have even more senses than people do.

            We’ve all seen how house plants begin to lean toward the light from the nearest window, but have you ever considered that to be a form of vision or eyesight? They detect the direction the light is coming from and grow toward it. They also know when another plant has grown over them, blocking their sunlight. And some can even detect different colors of light.

            Venus flytraps are the obvious example of a plant that has a sense of touch. As soon as a bug flies into its open trap and touches at least two hairs growing inside the lobe of the trap, the trap springs closed to capture and consume the insect. The plant can feel the prey touching the hairs and responds effectively.

            Plants can smell other plants, too. In many fruit trees, for instance, the smell of ripening fruit will induce nearby fruit to ripen more rapidly. They can also remember, sense up from down, and avoid obstacles.

            This is not to say, as University of Rhode Island botanist Keith Killingbeck warns, that plants that communicate are “old friends” or they “look out for one another.” That’s just anthropomorphism – giving human characteristics to non-human entities. "The novel research that has revealed the intricacies of plant abilities is captivating enough without the need to put an emotional smiley face on an oak tree," Killingbeck said.

            And while no one is claiming – yet – that plants have human-like intelligence or can feel pain, we do have much more in common with grasses and wildflowers and maple trees than most of us would have imagined a few short years ago.

            So next time you think you’re alone in the woods, think again. The plants may be watching you.

This article first appeared in The Independent on April 19, 2018.