Plants have desires … and the agency to meet them. So are they smart?

NPR was one of several outlets covering the release of writer Zoë Schlanger’s new book The Light Eaters: How the Unseen World of Plant Intelligence Offers a New Understanding of Life on Earth, which might reopen some old botanical debates about whether plants can be said to be intelligent. Ongoing research is demonstrating that plants really do demonstrate an awareness of their environment … and the ability to solve problems relating to it:

Schlanger acknowledges that our understanding of plants is still developing — as are the definitions of “intelligence” and “consciousness.” “Science is there [for] observation and to experiment, but it can’t answer questions about this ineffable, squishy concept of intelligence and consciousness,” she says.

But, she adds, “part of me feels like it almost doesn’t matter, because what we see plants doing — what we now understand they can do — simply brings them into this realm of alert, active processing beings, which is a huge step from how many of us were raised to view them, which is more like ornaments in our world or this decorative backdrop for our our lives.”

I was able to go to a lab in Wisconsin where there [were] plants that had … been engineered to glow, but only to glow when they’ve been touched. So I used tweezers to pinch a plant on its vein, … the kind of mid-rib of a leaf. And I got to watch this glowing green signal emanate from the point where I pinch the plant out to the whole rest of the plant. Within two minutes, the whole plant had received a signal of my touch, of my “assault,” so to speak, with these tweezers. And research like that is leading people within the plant sciences, but also people who work on neurobiology in people to question whether or not it’s time to expand the notion of a nervous system.

There’s one concept that I think is very beautiful, called the “memory of winter.” And that’s this thing where many plants, most of our fruit trees, for example, have to have the “memory,” so to speak, of a certain number of days of cold in the winter in order to bloom in the spring. It’s not enough that the warm weather comes. They have to get this profound cold period as well, which means to some extent they’re counting. They’re counting the elapsed days of cold and then the elapsed days of warmth to make sure they’re also not necessarily emerging in a freak warm spell in February. This does sometimes happen, of course. We hear stories about farmers losing their crops to freak warm spells. But there is evidence to suggest there’s parts of plants physiology that helps them record this information. But much like in people, we don’t quite know the substrate of that memory. We can’t quite locate where or how it’s possibly being recorded.