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The vining plant Boquila trifoliolata, found in the temperate rainforests of Chile and Argentina, has been challenging what we know about how plants work. It is able to alter almost every aspect of its leaves, including the size, shape, color, orientation, and stalk length, in order to blend in with its surrounding plants. Boquila has been found to mimic the leaves of more than a dozen species of trees and can even grow multiple leaf shapes on a single vine.
Researchers have hypothesized that the vines are receiving the genetic blueprint to make these new shapes directly from those neighboring leaves through a process known as horizontal gene transfer. In 2021, some of the same researchers that originally described the shape-shifting properties of Boquila vines came up with a plausible mechanism for these plants swapping genes. They suggested that airborne bacteria carry genetic material from the neighboring plants to Boquila’s leaves, which can then integrate that information into their own genes and use it to change shape. To test this, they sequenced the DNA in bacteria from Boquila leaves as well as the leaves from plants it had copied, and found an overlap between Boquila and the mimicked plants. These results hint that bacteria may be playing a role in the exchange of genetic material, which would be a pretty revolutionary idea, botanically speaking. That said, the authors also acknowledge that more has to be done to lock down this hypothesis. It’s a pretty extraordinary claim; it would need pretty extraordinary evidence.
But there is another even wilder possibility for how Boquila has become a master of disguise. A recent study has explored the rather controversial idea that these vines can see. The science-fiction-y idea that plants might be able to see has been around since 1905. That’s when Austrian botanist Gottlieb Haberlandt suggested that the outer layer of cells on a leaf could act as a lens, focusing the rays of light onto light-sensing cells, which all together is called an ocellus.
We have found some forms of photoreceptors in plants, but whether they allow plants to actually see shapes or colors, or even exist at all, has yet to be confirmed. But that hasn’t stopped researchers from exploring the idea of plant vision in Boquila. In a 2022 study, researchers decided to give some Boquila plants an eye exam. Since they knew that Boquila can mimic living plants, they decided to see if the vines could copy fake, plastic plants too. Since a plastic plant doesn’t have any genes to transfer, it would mean that if Boquila was able to mimic these leaves, it was not doing so by using genetics or any chemical signals from the host.
They also grew other vines below a shelf, blocking their line of sight to the fake plants. As the Boquila vine grew toward the artificial plant, its leaves started to morph, reportedly becoming more like the fake leaves, while the Boquila branches hidden by the shelf got bigger, but didn’t change shape. All of which, the authors argue, supports their idea that Boquila can see.
Now to be clear, other plant biologists are pretty skeptical of the plant vision hypothesis, going as far to call the idea “far-fetched”. Not only that, but several researchers have criticized the design of that 2022 study, saying the variables that can influence leaf shape, like the age of the leaves and light exposure, weren’t properly controlled for. They also criticized the lack of explanation for how plant vision could reasonably work, since the whole hypothesis hinges on the plants, like, actually being able to see stuff.
But the study’s authors stand by their work, and are currently doing more experiments with Boquila plants to further investigate their plant vision hypothesis. And even the critics will concede that they won’t say it’s impossible that plants can see. We might even find that both horizontal gene transfer and plant vision are at play when these guys mimic their neighbors.
These weird copycats are just one more example of how little we really understand about the natural world! ‘Cause who knows? Maybe when you look at that houseplant on your desk, it’s looking back at you. Regardless of how they do it, you have to admit that it is pretty cool these plants can shapeshift. They’re 3D objects that change into different shaped 3D objects!
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