Last year, environment writer Benji Jones drew attention to a plant so remarkable that it provides insight into why some scientists think plants are conscious.

Plant ecologist Ernesto Gianoli was strolling in the rainforest in southern Chile when he came across something unusual: The leaves of the familiar arrayán shrub were mimicked by leaves of a clearly unrelated plant, Boquila trifoliolata.

Commonly, the leaves of B. trifoliolata are stubby with three blunt lobes, but here, they looked just like those of the arrayán plant. It was as if B. trifoliolata was trying to camouflage itself in the foliage.

He walked around the forest looking for other B. trifoliolata plants, thinking this could be a fluke. Remarkably, roughly half of the other vines he encountered that afternoon had leaves that looked like other plants — not just other plants but the very plants growing next to them. 

Gianoli later established that different branches of a single Boquila plant can mimic different nearby plants. Plant biologists think that this ability is unique to Boquila trifoliolata. But how can they be certain? Did any plant biologist imagine that a plant could mimic more than a dozen other plants without even touching them?

Why does Boquila do it? Perhaps to avoid predators by mimicking less tasty plants. The main question though is, how do they do it if they can’t see what they are quickly adapting to mimic?

Wikipedia helpfully narrows the answer down: “The exact mechanism by which mimicry occurs is not well understood but may involve chemical, odor, genetic, metagenomic, transcriptomic, proteomic, metabolomic, epigenetic, and/or microbial cues to identify and mimic the species it is attached to.”

This list doesn’t appear to mention the controversial hypothesis that the plants can actually see:

How Could Plants See?

Searching for answers has intensified a fiery debate in the plant world. On one side are mainstream botanists, whose work is rooted in rigorous, repeatable studies, and on the other is a small group of researchers who believe plants share a number of attributes with animals, including humans. To the latter group, B. trifoliolata supports the idea that plants possess a form of vision and perhaps even a brain-like structure to process it. 

While Jones is clearly unsympathetic to the botanists who think plant vision is a plausible hypothesis, he admits that the Boquila vine is “pushing the boundary of what we know about plants.” Some have tried testing the vision hypothesis, based on the assumption that some cells in the plant function as simple eyes (ocelli), thus using light not only to process food but to interpret their environment:

Yamashita and his co-author, Jacob White (who’s not a scientist but raises plants at home), tried to test this by growing the mimic vine next to plastic plants. Their thinking was that if B. trifoliolata uses a form of vision for its mimicry, it should be able to copy any old plastic plant. And sure enough, it could, according to the study. “Leaves of B. trifoliolata mimicked leaves of the artificial plant,” it notes plainly.

Jones cites other plant biologists who discredit the methodology and the idea in general as too far out. The paper is open access.

The Sheer Awkwardness of the Problem

Elaborate plant mimicry, as well as plants that trap and eat animals, and show clever insect avoidance strategies, involves many complex behaviors. Something in the plants’ process of developing these behaviors appears to show intelligence. Thus, some scientists go so far as to argue that plants have qualities that are associated with intelligence.

That shouldn’t be surprising; some scientists now also think that bacteria are cognitive. As we’ve noted earlier, future debates over the origin of intelligence, consciousness, etc., may mainly feature panpsychists vs. theists rather than materialists vs. theists.

An alternative to the idea that such intelligence exists in nature — even in plants — is that there is an intelligence behind nature, as Stephen Meyer argues in Darwin’s Doubt (HarperOne 2013) and Return of the God Hypothesis (Harper 2021). That’s even more controversial, of course.

Either way, the traditional explanation — that natural selection acting on random mutation (Darwinian evolution) explains it all, without the need for any intelligence — is becoming increasingly untenable.