Savage Garden: Venus Flytrap Myths and Facts

In the world of carnivorous plants, the Venus Flytrap (Dionaea muscipula) gets all the attention. Despite the fascinating behavior of sundews, pitcher plants, and other carnivores, Venus Flytraps are the plants that attract interest and spark the imagination. Think you're an expert because you've seen Little Shop of Horrors countless times? Not so fast - we're debunking some of the most common myths about Venus Flytraps, and sharing some amazing facts instead!

Myth #1: Venus Flytraps are giant monsters. 
Fact: Venus flytraps are actually quite small, with the traps of the very largest topping out at an inch or two across. Even open wide, they're only about the size of a quarter. And the prey they catch is pretty small too. Which brings us to...

Myth #2: Venus Flytraps eat people.
Fact: People are much too large for a flytrap to digest. Mostly they eat insects like, well, flies. The Venus Flytrap can digest flesh from mammals, but it's not good for the plant, and might in fact kill it. Remember, the Venus Flytrap is a plant - it gets most of its food from the sun using photosynthesis. It traps and eats insects for other nutrients, and if it gets too many of them, it can sort of overload the system. Flytraps will even reject insects that are too large for it to digest properly. How can it tell? Well, that all comes down to the wonder of the trap itself.

That's an ordinary ant, only a centimeter or two long. Note that the trap is not much bigger.

Myth #3: Venus Flytraps bite.
Fact: Venus flytraps don't have teeth (or a tongue) despite their popular portrayals. But their actual trap mechanism is pretty cool, once you know how it works. The trap is actual the true leaf of the plant, supported at the end of a flat petiole, which many people mistake for the leaf. The outer edge of the trap is lined with large stiff cilia, but their job is just to keep prey inside once the trap closes. The real work of trapping is done by the six tiny trigger hairs (trichoma), three per side, on the inside of the trap. (Note the trigger hair easily visible on the top of the the trap in the photo to the below.)

Prey is lured into the trap by the red coloration and the sweet sticky mucilage on the trap surface. As the insect moves around and touches one of the trigger hairs, a timer of sorts is set off. If a second trigger hair is touched within 30 seconds, the trap will snap shut. As the prey struggles to escape, further contact with the trigger hairs causes the trap to close more tightly. Eventually, it seals completely, forming a chamber in which the digestive enzymes can go to work, breaking down the prey to extract the nutrients. (Learn more about the science of this process here.) After several days, the trap will reopen, displaying the husk of the insect inside. You can watch the fascinating process in this video clip from the BBC documentary series Life.



As you might guess, it takes energy to trap and digest prey, so the Venus Flytrap has evolved to be sure it's not wasting its time. If the prey in the trap is too small to be worthwhile, like a gnat or small ant, it may not brush the trigger hairs with the right timing, and if it does, it might be able to escape through the outer hairs before the trap seals shut. If the prey is too large, it will likely be strong enough to push the trap back open and flee. This keeps the flytrap from overeating.

Myth #4: Venus Flytraps come from exotic jungles.
Fact: Venus Flytraps are as American as mom and apple pie. These fascinating plants are native to certain boggy areas in North and South Carolina, including the Green Swamp. There are several non-native, naturalized populations in North Florida and Western Washington State, and the plant is extensively cultivated by nursery growers for retail sales. But the Venus Flytrap is notoriously difficult to care for in captivity, and its native range has been decimated by development, pollution, and poaching. Flytraps are classified as "Vulnerable" by the IUCN, and in many places it is illegal to collect them from the wild.

Some cultivars, like 'Red Dragon', are bred for their extra red coloration.

Myth #5: Venus Flytraps make good pets.
Fact: Venus Flytraps are pretty difficult to care for at home. Their growing conditions are very specific, and hard for most folks to replicate. It's also easy to kill a Venus Flytrap with too much love - every flytrap owner wants to poke flies and other items into the traps to see them work, but overfeeding is one of the fastest ways to doom this delicate plant. And triggering the traps without food is even worse, as each trap is designed to work only 2 - 4 times. If you set them off too frequently, they won't get a chance to do their job.

To grow successfully, Venus Flytraps need lots and lots of bright sunlight and very wet humid conditions, along with a cold winter dormant period each year. If you want to try it at home, we recommend you check out The Carnivorous Plant FAQ pages, which are full of detailed info. If it all seems like more work than you're willing to commit to, you might just be better off renting Little Shop of Horrors again - or visiting these beauties in a local botanical garden or science museum. If you're in Central Florida, we invite you to visit the Venus Flytrap collection in The Savage Garden @ MOSI Outside.