Photo by Erica Grivas: This photo illustrates 'canopy shyness,' where plants detect and leave space for each other.
Photo by Erica Grivas: This photo illustrates 'canopy shyness,' where plants detect and leave space for each other.
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The world of plants is as vast, and in some respects, as uncharted as the ocean floor. We have cultivated them for thousands of years as food and medicine; we’ve shaped them through selection and breeding, but we are only now discovering some rather amazing physical abilities they have. You might call them superpowers.
Recent research has shown that plants can communicate. They warn neighboring plants of predator or drought, they share resources, form inter-species alliances, and species like sunflowers and black walnut trees even attack competitors. When a species is grown in a grove, elder trees will send nutrients to saplings, who don’t yet have the leaf mass to photosynthesize.
The youngsters may even remember, or at least respond in unison. Peter Wohlleben, author of the sleeper best-selling book “The Hidden Life of Trees,” tells a story of a beech tree stump he found in a German forest. The rings marking the massive girth indicated it had been felled at least 400 years ago.
Yet when Wohlleben scratched the surface, green chlorophyll glinted through. His conclusion: The surrounding trees were care-taking this forest elder.
Plants have had internet tech for millennia before the dotcom boom — an underground webby network of mycorrhizal fungi — through which they send chemical signals of stress or well-being.  
One study out of Germany indicates trees know if they’ve been grazed by a deer, due to the telltale saliva, or had a branch broken by accident. In the first case, they whip up a chemical cocktail that makes their leaves taste terrible. In the second, they begin healing. My first thought was: Do humans have such a healing response, and can we naturally trigger it?
A plant attacked by a predator will mount a chemical defense to strengthen itself, similar to an immune response. In one experiment, some bean plants were allowed to form such a network, and some were not. When predatory aphids were added to a few plants, the ones in networks formed the chemical response. The ones without networks did not. Researchers suggested that this could be used to trigger responses only as needed, without over-stressing the plants continually, as can happen with plants genetically modified to resist an insect or disease, which triggers that stress response 24/7.
“Super plants” for climate change
We’ve known about plants’ ability to remove toxins from the air — thus those “top air-cleaning houseplant lists” online based on a 30-year-old NASA study that, unfortunately, doesn’t really extrapolate to home living. Your bedside snake plant will de-stress you, but it’s questionable whether it will convert your apartment into an alpine meadow. However, a new study from Britain’s Royal Horticultural Society shows one plant that may become the carbon-fixing future of our urban centers and highways.
The study, reported this month in The Guardian.com, compared the ability of various shrubs to absorb air pollution, including hawthorn, cotoneaster and red cedar. The hairy cotoneaster — a prickly, dense shrub with glossy leaves and red berries — was 20 percent more effective than the others, to the point that in seven days, a 3-foot dense hedge would “mop up the same amount of pollution a car emits over a 500-mile drive,” according to the lead researcher.
The RHS director of science and collections said they are investigating more of these “super plants” to answer the challenges of climate change, from ivy walls cooling buildings to hedges of privet and hawthorn used to disperse heavy rains and reduce flooding.
A better pothos?
Meanwhile, here at the University of Washington, researchers are trying to engineer plants to be better air cleaners, by taking the popular pothos houseplant and injecting it with a protein from mammalian livers — because it’s the same type of protein we use to break down alcohol. Hmmm.
Emails from spinach
An emerging field of study called nanobionics involves using plants’ ability to photosynthesize to turn them into living imaging systems, self-powered light sources and infrared communication devices. Nanoparticles inserted into the plant’s cellular structures accomplish these transformations. A recently published nanobionic experiment revealed spinach plants altered to become email-sending bomb detectors!
The plants, naturally able to detect certain chemicals in the ground, now set off a sensor, which triggered an e-mail.
As in all scientific expansion, the possibilities as to how we use our newfound knowledge are limitless, but we have a responsibility to consider the consequences. Do we use the plants as a Band-aid for our car pollution, or do we preserve more car-free space and plant more trees? Will we learn from plant’s technologies or simply exploit them?


Further reading:
https://www.theguardian.com/science/2018/may/02/plants-talk-to-each-other-through-their-roots#:~:text=Plants%20use%20their%20roots%20to,own%20unique%20forms%20of%20communication.&text=%E2%80%9CPlants%20can’t%20do%20that
https://www.bbc.com/news/science-environment-22462855
https://www.nationalgeographic.com/science/article/houseplants-dont-purify-indoor-air#:~:text=New%20research%2C%20however%2C%20continues%20to,the%20air%20in%20your%20home.&text=It’s%20a%20myth%20you%20almost,study%20the%20air%20we%20breathe
https://www.smithsonianmag.com/science-nature/the-whispering-trees-180968084/
https://pubs.acs.org/doi/10.1021/acs.est.8b04811
https://link.springer.com/chapter/10.1007/978-3-319-68717-9_14