True Facts: Plants That Explode

On a day like this one, you and I might think to sit it out and have a cozy day indoors. But for Liverwort, that unfortunately named plant that's a relative of moss, this is an Oppenheimer moment. Because they have figured out how to harness the energy of the raindrop to make a bomb. Sort of. You see, when it's time to make more Liverworts, they create a bunch of these. It looks a little like being backstage at the Nipple. Sitting inside these little pasties are spores. Little Liverwort babies. But the cup that surrounds them is just the right shape that if a raindrop falls into it, the babies go flying up to three feet away. And that's the thing with plants. Oh, all I need is some dirt, sun, CO2, and water. But you never ask what they're doing with all that water. And let me tell you, some plants are shady. They're not drinking it. You know what they're doing? They're making complicated explosives. I mean, one of the most straightforward is found in the Squirting Cucumber. The name's a bit of a spoiler, isn't it? Anyway, the fruit of these plants gradually fill up with seeds and a watery gel. And this builds up pressure. And when the pressure is great enough, it pops off the stem. Sort of a... I mean, it's a bit of a mess if you ask me. It's like the plant gets it all over itself. And you don't want to be covered in baby juice. Fortunately, many other plants have found a more nuanced way to spread their seeds with a boom. Take the flowers of the Bunchberry Dogwood, for example. Now, dogwoods are the ones where the leaves got all just and wanted to be flowers. And so now it's a whole thing. So here, these are leaves. And these ones inside are the actual flowers. Now, they start off with their petals all sealed up in a point, held together with a little strip of tissue. Those little knees that are sticking out are anthers. If you look inside, each one has a little shoe on the end with baby-making pollen all over it. And each shoe is on a flexible hinge. Anyway, you can see it's all packed in there. The cells inside these bent anthers fill up with water and slowly put pressure on that little strip that's holding the whole package together. One of the four petals has an extra bit that's sticking up. Stop it. That is essentially a trigger. Touch it, and... Those shoes are designed to shoot the pollen up. Or all over whatever triggered it. But these explosions aren't always about water building up. Sometimes it's about drying out. Now, you don't think of moss as being particularly sophisticated, do you? When moss in the genus sphagnum... That's a name. I've got an itchy sphagnum. Anyway, when it's ready to release its spores, it creates these little olive-shaped things. It even looks like it has a little pimento. At first, the cells that make up the outside of these little balls are flush with water, nice and plump. But sphagnum turns the spigot off, and they slowly start to dry out. As they dry, those plump cells start to collapse laterally, causing the whole thing to become more like a tube. This builds up pressure inside. And at the same time, the drying out causes that ring of tissue at the top to weaken, until suddenly... The force of this explosion creates a vortex ring, like a smoke ring, that carries the spores upward where they can catch the wind. Listen, if you're interested in learning new things as much as I am, you'll appreciate something that makes browsing a whole lot smarter. The Opera browser includes ARIA, a browser AI that can quickly give you context around any word or phrase you highlight while you're looking around. Sphagnum? What is it? Is it itchy? And while you're browsing, if something catches your eye or gives you an idea, Snapshot lets you grab a part of the screen, then edit it, take notes, and save it all without having to leave the browser. Now, if you want to go deep on a few subjects at the same time, Opera has separate workspaces you can toggle through in the sidebar. And in those workspaces, Tab Islands lets you organize tabs into context-based groups, which you can collapse, so you don't just start deleting tabs because you're overwhelmed. Along the way, if you want some inspiration on how to organize your thoughts, you can use ARIA to help you compose anything from a blog post to a presentation. And you can even train ARIA to write in your style. And I'm just scratching the surface here. There's integrated messaging, a built-in VPN, and a lot more. You should try it. It's all free. Download the Opera browser today by clicking the link in the description. Where were we? Oh, right. I know what you're thinking. Sneezing out spores and pollen, that's child's play. What about something with some more heft to it? Well, if you look close there, you might be able to see some witch hazel seed pods. When these pods dry, they open up a bit, and you can see the seed. The drying also causes the pod to shrink. This exerts a pinching force on the back of the seed, which is held in place by friction or a small layer of cells. They don't know. When the force is big enough to break that attachment, it sort of pinch-pops the seed out. But the seed doesn't just pop out willy-nilly. It has a spin to it. The spin creates a gyroscopic force that keeps the seed from tumbling and makes it more aerodynamic. A number of plants put some spin on their seeds. The habio tree puts a little backspin on its disc-shaped seeds. Same with the hairy wild petunia. My hairy wild petunia is a bit itchy as well. But all this spinning helps these seeds travel farther. But back to that witch hazel pod. You'll notice that as it dries, the two sides kind of bend back. And that's because there's a way to make things bend using moisture. Here, let's look at dead plants for a moment. Bear with me. On this top layer of wood, the grain goes the long way. And the bottom layer is made out of pieces where the grain goes the short way. All right, you glue it all together and then start drying it out. The way these pieces are arranged, the bottom layer shrinks more than the top. But it's glued to the top piece, so the only way it can shrink is to bend. So just by having layers that respond differently to changes in humidity, you can have something that bends on its own. That's how pine cones open up, for example. Their scales are built that way. So as it dries out, they bend, allowing the seeds to fall out. Creeping wood sorrel gets creative with his bendy-bendy business. Its seeds come in these pods, and each seed is surrounded by a little jacket called a who-gives-a-sh**-what-it's-called. As it matures, that covering becomes more transparent, and you can see the darker seed inside. Because of the way it's layered, as it takes on moisture, that covering wants to bend. So much, it wants to turn inside out. Kind of like one of those novelty poppers. But it's being held together by attachments along this seam. But wouldn't you know it, the seam has a weak point. And if you disturb it, the jacket unzips and turns itself inside out. And that launches the seed in the process. But these seeds have another trick. They try and bust out their siblings, too. You may have noticed that the jacket has a little hook in the back. And that lines up with the weak point in the next seed's seam. So if one goes, you can get a chain reaction. Now, depending on how these bendy-bendy layers are arranged, you can create spring-loaded pods that open up in all sorts of different ways. Ones that twist like the common vetch. Ones that curl up in a fancy mustachio. Or those badass exploding spirals of the impatiens. But there's another cool thing about these self-bending layers. The bending is often reversible. They can bend, but when humidity changes, they can straighten out again. If you put an open pine cone in water, it'll close back up. Spores of the horsetail use this back-and-forthiness to do something amazing. You can see it right there. They're spreading their little arms out like a parachuter. Each spore has these four little strips hanging off them that are humidity-sensitive bilayers. When they're wet, these strips curl up in a tight little ball around the spore. But when they're dry, they open wide and spread out like a yoga pose. They look so happy. I know it doesn't seem like much, but these basic movements allow these spores to sort of walk. Taking advantage of small fluctuations in humidity on the ground. All right, they're not winning any races, but look at them. Once these spores land, they can move around a bit and find a spot that's suitable for them to open up. But sometimes when they ball up, their arms will stick together because of friction. And if things dry out suddenly, that friction will act like a latch, building up tension as the arms want to open up until pop! And that sudden release makes them jump. The seeds of wild oats do something similar, but at a much larger scale. Each seed has these two long hair-like bristles sticking out the back, called none of your f***ing business. Sorry, they're called get off your lazy ass and google it. All right, they're called awns. Gotta do everything. Now when they get wet, these awns start twisting around in a circle, and the top half flexes a bit like a knee. This motion allows the oat seed to sort of roll along. Like if you were laid down with a bad case of the spins trying to make your way to the toilet. But one of the awns is longer than the other, and that means the two twist at different rates. So from time to time, the two awns will hit each other and lock together. And that means some tension can build up until they hop! Now this isn't just to win the best worst impression of a grasshopper contest. What these seeds are doing is looking for a way to bury themselves into the ground. Now they might get lucky and twist themselves into a pre-made hole. Quite fortuitous. Almost looks like a science hippie used his fingers. I'm onto you people. But if the head of the seed gets some purchase on the soil, The motion of the seeds against each other and their surroundings allow the seed to bury itself. Like a screw. But in terms of screwing, these oats have nothing on the stork bill. The stork bill is like a greatest hits. When its fruits dry out, they explode, sending five seeds out, each with its own awn. Little bit of a spermy vibe. When they're wet, these awns are fairly straight. But as they dry out, they twist up like two snakes that gotta go potty. Makes no sense. Anyway, you know what I mean. You're looking at it. The part closest to the seed does the coiling, while the top of the awn just kinda hangs out. The curling and uncurling allows them to move around a bit. But when they get at the right angle, the barbed tip of the seed can find a crack in the soil. And then the whole thing becomes an incredibly efficient vehicle for writing sex jokes. With the screwing and the moisture and the twist, it's a bad joke machine. And it plants a seed, so it does both. Anyway, some science hippies caught a whiff of this screwing action. And they were like, I bet there's some other seeds that wouldn't mind drilling dirt. So they used the design of the stork bill to create a version that could carry other seeds. And these things use humidity in the same way. And look at that, they work! It's a little tiny baby plant. Hey, did you know there's seeds that explode? You and me sitting here just getting old. We got to blow, blow. We got to blow up like seeds that explode. I know that some of you are bothered that this popper never popped, so... Hey, did you know there's seeds that explode? You and me sitting here just getting old. We got to blow, we got to blow. We got to blow up like seeds that explode.