How Do Venus Flytraps Work?

the venus flytrap. The venus flytrap grows roots, stems, leaves, flowers, and seeds just like most plants, but it also grows two specialized lobes on the end of each leaf that form a hinged trap. Those lobes are distinctively green on the outside and reddish pink on the inside, with small bristles along the edges. But when they're open, they look

like toothy little mouths calling for a snap. And when an insect or a racknid crawls across that pinkish inner surface, the trap slams shut and the plant digests its prey. It's a mouth and stomach in one. Although the venus flytrap has captivated people across the world. Wild populations of these plants actually grow in an incredibly small geographic area, a region along the coasts of North and South Carolina, only some seventy five square miles in area, that's about

two hundred square kilometers. Their native areas are bogs and wetlands that are humid and sunny. They're so scarce that some early botanists doubted their existence despite all the stories spread about a flesh eating plant. But okay, if other plants can thrive on nothing but water, air, nutrients in the soil, and some sunshine, why do venus flytraps eat insects? Flytraps actually get a good deal of their sustenance just

like other plants do. During photosynthesis, plants use the energy of the sun to drive a reaction that converts carbon dioxide and water into sugar and oxygen. The sugar produced is then converted to energy that the plant cells can use a molecule called adenosine triphosphate or ATP. ATP is

what our cells used to get stuff done too. However, in addition to sugar, plants also need to make amino acids, vitamins, and other cellular components to survive in the coastal bogs where venus flytraps live, the soil is acidic and minerals and other nutrients are scarce. Most plants can't survive in this environment because they can't make enough of the building blocks necessary for growth. The venus flytrap evolved an alternate

means of getting those key nutrients. Living creatures like insects provide a good source of the stuff that's missing from the soil, plus additional carbohydrates so that covers the y. But how do these plants catch and eat prey. A plant doesn't have a brain or even a nervous system to coordinate their functions and movements, nor do they have bones, tendons, and muscles to coordinate. But most plants do have some way of attracting animals or insects, regardless of whether they're

going to eat them. Lots of flowering plants have evolved colors, scents, and sugary nectar to attract bees, butterflies, and other pollinators. In those cases, the animals get a snack, and they unwittingly ferry the plant's pollen to neighbors of the same species, thus fertilizing them. Hopefully. Similarly, fruits evolved to be sweet and tasty because if a bird or other animal eats them and later poops the seeds elsewhere unharmed, a new

plant can grow. In the case of the venus flytrap, the inner surface of those specialized lobes secretes a sweet

nectar that draws in insects searching for food. But the inner surfaces of the lobes also sport short, stiff, hair like structures that serve as a sort of motion to When a creepy crawley crawls across the surface and brushes two hairs in close succession or one twice, the lobes close down in as little as half a second, trapping the creature inside a fun fact or black thereof No one knows exactly how this works, ever since Charles Darwin

described the species in eighteen seventy five, and he called it the most wonderful plant by the way. Ever since then, researchers have been trying to get to the bottom of this trapping mechanism, but it's difficult to observe what's going on inside a living plant during half a second of action. The prevailing hypothesis goes that a venus fly trap accomplishes this feat by rapidly changing the geometry of those specialized lobes via water transfer within the lobes upon stimulus. Let

me break that down, Okay. Each lobe or half of a venus flytrap's trap seems to have two functional layers inside, an upper layer up against the pinkish interior surface of the trap and a lower layer up against the green outer surface of the trap. Cells within the layers contain water. That's not unusual. Cells generally do contain water, but the upper and lower layers are each capable of holding onto water and of transferring it quickly to each other. When

the trap is open. That's actually a tense state for the lobes of the leaf, wherein more water is being held by the upper interior layer of cells. This makes each lobes slightly convex and holds the trap open. But when something triggers those motion detector hairs that somehow tells the plant to open up pores between the upper and lower layers, water quickly moves into the lower outer layer, making each lobes lightly concave, curling in around its prey.

In a fraction of a second, this closed state is relaxed for the lobes of the leaf. They open back up again by slowly transferring water back to the upper interior layer, but it takes a while. Again, no one entirely understands how all this works, though there is some interesting research into all the biochemical details. But for our purposes today, let's focus in on what happens when that

trap does close on some tasty prey. The lobes of the leaf form an airtight seal so that digestive fluids and insect parts are kept inside the trap, and so that bacteria and molds can't get in. Those toothy looking spines on the outer edges of the trap laced together and latch the trap shut. There is an upper limit to the size of insect that a trap can accommodate.

The traps will grow up to around an inch long or about two and a half centimeters, and in order to close tightly, an insect that catches can only be about a third of that size. If an insect is too large, the trap can't form a seal against microbes, which will move in and eat the decomposing insect and the trap itself too. The trap will turn black and drop off of the plant, but back to dinner. Once an insect or a rapnet is firmly ensconced in the trap,

the process of digestion can begin. The trap now serves as a miniature stomach, just like our stomachs. The trap secrete acidic digestive juices that do three things. They dissolve the soft tissues and sell membranes of the food. They serve as an antiseptic to kill any microbes that got in with the food, and they break down various proteins and other molecules into small pieces that the plant can

take in. It takes some five to twelve days for a trapped digest prey, depending on the size of the prey, the age of the trap, and the ambient temperature. Older traps and colder temperatures make digestions slower. The process continues until all that's left of the insect is its herd exoskeleton and its bath of digestive juices. The plant reabsorbs the fluids and the trap slowly reopens, after which the praise remains are usually either washed away in the rain

or blown away by the wind. A venus fly trap can tell the difference between living prey and a dead exoskeleton or other non edible debris that might fall in. Inanimate objects that trigger the trap's motion sensitive hairs won't keep moving once it slams shut. If there's no further stimulation of the hairs, the trap won't seal up, but it will be stuck in partially shut state until tension can be re established in the lobes of the trap. This process takes about twelve hours, at which point the

unwonted object falls out. This selection process is pretty good, but not perfect. While the trap is out of commission, real food may be crawling all around the plant. Imagine if you had to sit with a chicken bone or peach pit in your mouth for twelve hours while the rest of your dinner sat on the table in front of you. Of course, the venus fly trap doesn't feel any kind of way about it. It's a passive participant in the process of eating dinner. Any given trap won't

last the full lifetime of the plant. After about ten to twelve closures, either partial or complete, the trap will stop trapping and remain partially open. It'll devote its remaining time to photosynthesis, usually for around two to three months, while our imaginations dream up people eating killer plants. In reality, we're the threat to venus fly traps and other carnivorous plants in the wild. Venus fly traps today only cover about a third of their historic range. In the nineteen seventies,

there were around four million of them. That's down to just over three hundred thousand as of twenty twenty due to over collection by humans and the draining and destruction of the natural wetlands where they grow. There's a hefty fine North Carolina felony charge for removing them from the wild, but lots of reputable plant nurseres propagate and sell them legally. If you grow one at home, you'll be looking to replicate its boggy, bright homeland with specialized soil and humid conditions.

A terrarium can help. Check growing guides online or talk to your local garden center. A venus flytrap will grow to about five inches or thirteen centimeters tall, with about four to eight traps per plant. You'll want to provide it with two or three small flying insects like a house fly every month. A far cry from the feed me seemore eating habits of carnivorous plants in science fiction.

Today's episode is based on the article how Venus flytraps work on HowStuffWorks dot Com, written by Anne Mieker O'Connell. Brain Stuff is production of iHeartRadio in partnership with HowStuffWorks dot Com and is produced by Tyler Klain. Four more podcasts my heart Radio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.