The Creepy Tree Conversation in 'The OA' Is Actually Based on Real Science

the oa
The trees are gossiping right now!!! | Netflix
The trees are gossiping right now!!! | Netflix

This story contains spoilers for Season 2 of Netflix's The OA.

By the time the new season of Netflix’s The OA gets to the giant telepathic octopus, you think you've seen it all. And then, just an episode later, the main character of the show falls through the ground and has a conversation with the roots of a giant tree. The tree, and its nearest tree brethren, tell O.A. (co-creator and star Brit Marling) that they've been calling to her for years, and she hasn't answered, and then they give her a warning about her future. This conversation, like many of the ideas in the show, may seem like wild fantasy, but (also like many things on the show) it’s actually based on real scientific theory.

We can't actually talk to trees, but trees certainly do talk to each other -- all the time. This has been pretty common knowledge amongst naturalists for a number of years, who have studied forests' interconnected underground networks and found out that trees communicate through their roots using the mycelium of a fungus: intertwining with each other, checking each other's growth, feeding their comrades, sending warnings to their friends, creating a web of information not unlike the sparking neurons of the human brain.

When a tree dies, often it will release the nutrients it won't use anymore into its root network, so that the trees nearby can benefit. If a pine is being attacked by bark-eating beetles, it sends signals to the other trees around it so they can marshal their defenses. Some species will steal nutrients out of the network from other trees nearby so that they can grow bigger, taller. If an overconfident sapling is growing too fast, its larger, older mother will seep away some of its food so that it slows down, keeping it from breaking through the canopy too early, which would kill it for any number of reasons (snapping, overexposure to sunlight, etc.).

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O.A. has a chat with a tree. | Netflix

In Season 2, Episode 5 of The OA, titled "The Medium and the Engineer," O.A. and Karim venture into the mysterious mansion that's been luring people into its depths. They separate, and O.A. finds a window looking out on the large tree growing in the house's front yard. She steps out onto a branch, but it cracks, sending her plunging down through the ground until she's caught by a large root, which forms itself around her like a chair. As soon as she arrives, glittering messages expand outward like ripples amongst the roots of the trees. There are even shots of little fungi bubbling in excitement. The trees called her with the wind, they say -- the very same wind O.A. heard when she was shot outside the school in the Season 1 finale.

"The one who seeks to own you is going to make a powerful discovery," they tell her, hinting at Hap's knowledge of the seeds in everyone's brain, and how he can use them to build a rudimentary map of the multiverse out of leaves and roots. "The only way to recover is to form a tribe," they say. When O.A. insists that she can figure out how to escape by herself, the trees disagree: "No tree survives alone in the forest. When one tree falls ill, we all send food. For if one tree dies, the canopy is broken. Then all suffer the weather and pestilence that flood in." The family O.A. built for herself in Season 1, with Steve and Buck and French and B.B.A. and the others, are vital to her survival. No one can do all those movements by herself.

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Season 1's terrarium prison was full of plants. | Netflix

So, OK. Marling has watched at least one TED Talk. But, whether intentional or not, this new fantastical element fits in perfectly with everything else Marling is doing with her show. Since the very first episode, The OA has been conspicuously full of greenery, even in places where it shouldn't be. When Buck's family has packed up most of their items for their move, their house plants still crowd the kitchen, crouched on top of the cabinets, the counters, the fridge. The floor of the mystery house, the magnetic tiles of which O.A. and Karim rearrange, ends up depicting the concentric rings of a very large tree trunk. Even in Season 1, half of which took place inside a basement prison, Hap's captives shared their terrarium cells with a jungle of greenery, which purified the atmosphere and clouded the glass walls with water vapor.

"There is a seed inside every brain," Hap says right before serving up Season 2's most bizarre development. As he watches, a tiny sprout grows out of a boy's submerged ear, putting out a little leaf as soon as it breaks the water's surface. These seeds are later revealed to be the building materials for an interdimensional map. When O.A. finally confronts Hap inside his laboratory, she finds a swimming pool full of bodies fueling their own water lily-like plant systems. Hap describes the multiverse as "an actual garden of forking paths within us all," made up of every decision and possibility in our own lives, each of which leads to a new possible reality. The natural world and all its mysteries is a vital component of The OA, at its most compelling and powerful when it takes root just below the surface.

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Emma Stefansky is a staff entertainment writer at Thrillist. Follow her on Twitter @stefabsky.