JUANA SUMMERS, HOST:
All right, Ailsa, pop quiz - how many cucumbers can you name?
AILSA CHANG, HOST:
(Laughter) Well, there are Persian cucumbers - the itty-bitty ones. And then there's the super long English cucumber, right?
SUMMERS: Go on. Go on.
CHANG: That's all I got, Juana.
SUMMERS: Well, Ailsa, our next story is about a kind of cucumber that science reporter Ari Daniel says uses ballistics to spread its seeds.
ARI DANIEL, BYLINE: Three summers ago, when Helen Gorges' Ph.D. supervisor returned from his annual vacation to coastal Turkey, he had a present for her.
HELEN GORGES: He came back and was like, Helen, I brought you something. They might explode, but maybe you can work on them.
DANIEL: He brought her a handful of squirting cucumbers.
GORGES: It looks like a small, hairy cucumber, actually. So this cucumber is toxic, so you shouldn't eat the fruit, you shouldn't eat the seeds and also not the leaves.
DANIEL: The squirting cucumber doesn't get its name for nothing, and it's why her supervisor, who studies biomechanics, was so excited about them. Gorges searched for the plant on YouTube and turned up this David Attenborough video.
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DANIEL: Attenborough reclines next to a patch of the cucumbers. Each one is puffed up with fluid and seeds, pressurized and ready to burst.
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DAVID ATTENBOROUGH: All they need is just a slight nudge.
DANIEL: He barely touches a stick to one, and it pops open...
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ATTENBOROUGH: (Laughter).
DANIEL: ...Expelling its seeds in a fraction of a second, which he says allows them to germinate some distance away, reducing competition with their parent. Gorges, who's based at Kiel University in Germany, was hooked.
GORGES: We just wanted to know how the whole explosion works, actually.
DANIEL: The first thing that she and her colleagues did was take a few hundred photos of different cucumber specimens to measure the angle between the stem and the ripened fruit, which was consistently a touch more than 50 degrees.
GORGES: With air resistance, it just is the perfect angle so that they can shoot as far as possible.
DANIEL: Gorges then wanted to examine the ejection of the seeds in greater detail. But you can't expect to see anything by just watching a squirting cucumber in action. It's way too fast.
GORGES: I haven't seen it before, how the explosion really looks like.
DANIEL: So Gorges used high-speed videography. When she later slowed the video down, she observed the stem lifting off and a jet of fluid spurting out, accompanied by one seed shooting out at a time.
GORGES: The seeds, they really all come out in the same direction.
DANIEL: Gorges calculated the seeds can reach velocities of up to nearly 30 miles an hour, and they can launch themselves almost 40 feet. CT scans of the fruit's interior revealed the seeds lined up in rows, awaiting their ejection, round end first. The results are consistent with a study published late last year by a different team in England.
GORGES: So the plant is crazy. So the fruit really prepares for perfect dispersal - as far as possible so that the plant will grow everywhere.
DANIEL: Gorges and her colleagues then went on to examine the seed's mucilaginous coat and how strong it was when it's stuck to a glass slide and then dried. She found the adhesive was so strong that a single seed could support as much as a 6-pound weight. Gorges presented her results at last week's Society for Experimental Biology conference in Belgium. Sheila Patek is a biologist at Duke University who wasn't involved in the research.
SHEILA PATEK: If adhesion is what it's all about, then, in fact, the remarkable launch velocities may have more to do with making sure that when that seed hits something, it sticks.
DANIEL: So that it might be carried farther by whatever it's stuck to - Patek says the discoveries may well have applications.
PATEK: These types of materials that these folks identified in this study are really translatable in today's world of material science.
DANIEL: Including soft robotics that might disperse seeds on farms or deliver drugs in the human body. And these seeds, whose stickiness changes when wet, could help inspire materials designed to work differently in damp or dry conditions - not bad for a little squirt. For NPR News, I'm Ari Daniel.
(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.
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