[INTRO ♪] Lots of animals are known for their wily ways, but other forms of life also have a few tricks up their sleeves. Since they spend most of their lives anchored to one spot, plants can’t exactly run away if they’re attacked, and they often need to convince more mobile critters to help them interact with their mates. So, some species use deception to get what
they want. By dressing up like other plants or smelling like an attractive mate, the plants on this list can trick all sorts of smarter species—even us. You might not like it when someone says you look like poop, but if the seeds of the South African restiad could think, they would probably consider that the ultimate compliment. An unassuming, grassy-looking plant, the restiad goes to great lengths to dress its seeds up as feces. Eland antelope feces, to be precise. It’s an attempt to trick dung beetles into
doing the hard work of moving their seeds around. Plants need space to grow, so seeds need some way to get out their parents’ shadows, quite literally. Many can rely on small mammals that hoard seeds, but there aren’t many good hoarders in the South African shrublands where these restiad plants live. Apparently, dung beetles are the next best thing. The beetles in question both consume antelope feces and use it as a cozy little nursery for their babies. So when they find a nice turd, they quickly
roll it to an opportune spot and bury it for later. The plants’ seeds look and smell strongly like antelope poop—enough to fool the beetles, anyway, which roll and bury the seeds some distance from their parent plants. The burying also protects the seeds while they germinate, so the plants can rebound quickly after fires burn through the dry landscape. Meanwhile, the poor beetles end up with nothing
for their labors. The common lungwort also does its best poop
impression, but for the exact opposite reason. To deter animals that might otherwise munch on them, they make their leaves look like a Jackson Pollack—if he painted with bird droppings. Most plant eaters steer clear of leaves covered in droppings for the same reasons you wouldn’t want bird poop all over your salad. Droppings don’t really provide any nutritional
value, might not taste so great, and could
contain diseases or parasites. And the lungwort’s ruse might even work on smaller leaf-chewers like caterpillars that have a lot to lose if hungry birds are around. It’s possible the patches are meant to mimic fungal damage instead of bird poop, but either way, the ultimate message is the same: don’t eat these leaves; they’re gross and potentially pathogenic. White patches are relatively cheap as far
as defenses go, though not entirely free. The blotches can’t photosynthesize, so spotted leaves can’t produce as much fuel as unspotted ones would. Even so, the plants’ poop-like patterns are the most intense when they’re growing in darkly shaded spots, perhaps because the lower light means they can’t afford to lose as many leaves. And a few light patches of bird poop aren’t
enough, I guess? Pebble plants get their name because ...
they look like pebbles. Which turns out to be a great way not to get
eaten, because pretty much nothing eats rocks. They’re a kind of succulent—juicy plants that store water in their tissues, allowing them to eke out a living in lands too dry for most plants. That water makes them a prime target for all
kinds of thirsty animals, in addition to the hungry ones. So, they disguise themselves like rocks. Their pebbly shape is made by pairs of leaves
folded inward, creating a sort of inverted pyramid. Those leaves are adept at absorbing water from fog, dew, and rain, which is then stored in the plant’s fleshy interior. Meanwhile, calcium oxalate crystals in the
plant’s outer layer give it a stony gray exterior, while reddish pigments in its tissues help it perfectly match the pebbles around it. This kind of simple mimicry of something unpalatable is known as Batesian mimicry, and these certainly aren’t the only plants that employ it. But they’re just so much better at playing
pebble than anything else. It’s not until the fall when their daisy-esque
flowers bloom that they reveal their plantishness. Blending in has lots of advantages, and no plant has mastered the art of camouflage better than the chameleon vine, a climbing vine found in South America. Every other plant on this list is limited
to one costume, whereas these vines can reshape themselves to mimic at least 8 different plants. They can even have different leaf shapes in
different parts of the exact same vine! This rare ability to don multiple costumes
is called mimetic polymorphism, and it’s otherwise known only in butterflies. The plant is somehow able to alter just about every trait of its leaves, from their size and shape to their spininess and even the pattern of veins, which does a great job of hiding the vines from hungry mouths. The thing is… no one knows how the plant
figures out what to look like. It changes its leaves even when it’s not
in direct contact with the plant it’s mimicking, and it’s not like they have eyeballs to
see what to mimic. Or… do they? A 2016 paper revived an old and controversial idea that these and other plants may be able to, quote, “see” things like color and shapes through light-sensing structures called ocelli. But no one has investigated these in the chameleon
vine specifically. Other researchers think it’s more likely the vines pick up on chemical signals from nearby plants, and somehow translate the pattern of compounds into the right leaf size, shape, and color. But … no one has ever found an airborne chemical that induces this vine—or any other plant for that matter—to change its physical leaf traits this way. So exactly how it pulls off its incredible
deception remains a mystery. The Asian dancing plant is a favorite of gardeners for its unique, mobile leaflets which make elliptical patterns every few minutes. Those smooth moves are thanks to a special ring-shaped organ at the base of each leaflet, called the pulvinus. Its cells can swell or shrink by controlling
their water intake, allowing the leaflet to swerve around. Sunlight and warmth seem to speed their movements up. And some people swear they dance in response to music, suggesting that some kind of vibratory cue could be in play. Why they do this at all, though, has perplexed
scientists for centuries. Today, some researchers think they’re mimicking butterflies, trying to imitate the subtle wing shifts butterflies make when they’re resting in the sun. And that might be because butterfly larvae are a big problem for many plants, and butterflies don’t like to crowd their young. So it’s possible the dancing leaves protect the plant by making it appear occupied to butterfly moms— basically, pretending that this
prime real estate is already taken. Another suggestion is that the leaves attract various creatures that eat butterflies or other winged insects. If those predators are hanging around, they can snack on any actual insects that try to munch on the plant. Or the plants could have bouncing leaves for some other unknown reason, because the butterfly hypothesis hasn’t been well-tested. But it makes a lot more sense than the idea
that they just like to boogie to a good beat. So far, we’ve seen plants that deceive to
disperse their seeds and others that disguise themselves to avoid being eaten. But there’s another reason a plant might want to lie, and it’s one that some people can probably relate to:
to find a mate. Many plants rely on pollinators to help them do that. And sure, they could lure helpful animals in with a tasty nectar treat, but those sugary rewards are costly. So lots of plants employ more nefarious tactics—especially orchids, which sometimes disguise their flowers as insects eager for a mate. Take the hammer orchids of Australia, for example. One petal is modified into a hammer-like labellum that’s shaped, colored, textured, and scented like a female wasp. This part is connected to the rest of the
flower with a hinge, so when a male wasp lands and starts mating with the decoy, it swings and slams him into the flower’s pollen. When the unlucky bachelor falls for the same trick again on another orchid, the pollen is jammed right where the orchid needs it. Orchids aren’t the only plants that trick
pollinators, though. Aroids, a family of flowering plants, have also mastered the art of olfactory deception. And one of the most impressive examples is
a species of American pipevine. It’s so named because its flowers bear a
vague resemblance to an old-fashioned pipe, but that’s not what they look like to the
small biting flies that pollinate them. These flies—or no-see-ums as they’re often
called—feed on mammalian blood. So they jump at the chance to nestle into a nice, cozy rodent or rabbit ear, with its easy-to-access flesh full of juicy capillaries and veins to drink from. That’s why the flowers are somewhat ear-shaped and furry-looking, they emit a musty odor, and are mottled with blood vessel-y pinks and browns. When a fly touches down inside this fake ear, the slick surface sends it barreling into the pipe, where it’s trapped by backwards-facing hairs. It can remain stuck there for days while the
plant covers it in pollen. Then, the hairs wilt, and the fly is freed—hopefully to find another fake ear and deliver that pollen. The last plant on this list earned its spot
for one big reason: the species it tricks is us. This grass is considered one of the world’s worst weeds, and one variety is almost indistinguishable from rice. But it wasn’t always. Barnyard grass originated in Asia, where it
was quite at home in damp habitats. But then agriculture took the world by storm, and around 12,000 years ago, people basically everywhere started farming crops like rice. Those well-maintained, periodically flooded
fields were the perfect habitat. But their farmers disagreed, and set about plucking the grassy weeds out by hand whenever they saw them. Which put a very specific kind of evolutionary pressure on the weed to blend in. If the weed was growing in a hand-weeded rice paddy, it was more likely to get missed if it looked a bit more like rice. And over the centuries, a new growth form
emerged. This variant of the weed has seedlings that
look almost identical to rice seedlings thanks to their size, coloration, and more erect leaves. And the mimic weed’s seeds are 2-3 times
as heavy as the seeds of its kin— much more like the size and shape of rice grains. In fact, the weed looks more like rice than
it does other members of its species. This case of mimicry is especially stunning because barnyard grass isn’t even closely related to the rice it pretends to be. So unlike other crop-mimicking weeds, it didn’t steal genes from the rice to look more like it. And unlike the other plants on this list, its tricks aren’t meant for some beetle or cud-chewing herbivore. They’re meant for—and work on—us. It may not be the flashiest example of deceit,
but it’s certainly the most personal. Whether they’re fooling a rice farmer or a dung beetle, all of the examples on this list should give you some idea of just how tricky plants can be. Which just goes to show that you don’t need a brain to deceive. And evolution can produce some pretty incredible liars. Thanks for watching this episode of SciShow, which was brought to you by our patrons on Patreon! If you want to help us keep making videos like this, and get access to cool rewards like exclusive blooper reels, just head over to patreon.com/scishow. [OUTRO ♪]
