From the Little Shop of Horrors to the Attack of the Killer Tomatoes, carnivorous plants have always captured our imagination. However, beyond Venus flytraps (which I knew existed thanks to an eccentric kindergarten teacher who once fed one in front of class), I always thought the imagination was the only place they actually existed. Turns out I was wrong. Several botanical gardens have extensive collections of these hungry plants, which are so bizarrely fascinating, the Post just had to investigate further.
They typically live in tough habitats. For survival, they capture scarce nutrients not through soil, but through bugs and, sometimes, larger prey. Carnivorous plants vary greatly in size, shape, and “hunting” method. Below are several examples from the wild world of carnivorous plants. If you would rather skip the info and just watch plants eat stuff, feel free to click on the videos or pictures above each one.
Fortunately for us, no variety of Venus Flytrap is actually big enough to eat people. They are, however, big enough to eat things larger than you would think (see video). Flytraps produce appendages at the end of their leaves that look like a cross between a flower and a butterfly, with eyelash-like things protruding from the sides. Like many carnivorous plants, they attract prey by producing sweet sap. When animals take the bait, they activate small hairs on the appendage that trigger it to snap shut like a bear trap. The “eyelash” projections interlock so that the unfortunate creature is locked in. The snapping mechanism of the flytrap is an example of one of the most unusual plant features in all of nature–rapid plant movement. Unlike slow plant movement, which many plants exhibit (for example, when they turn leaves with the path of the sun), rapid movement is highly specialized and rare. It is also impressive, considering plants have no muscles.
Star Wars fans might find the Nepenthes interesting, because it reminds one of the Sarlacc, Jabba the Hutt’s favorite means of disposing those who didn’t pay up. Certain species are among the biggest carnivorous plants. For example, the rare Nepenthes attenboroughii (named for British botanist Sir David Attenborough) has, over thousands of years of isolation, become large enough to eat rats! Although there is debate as to whether the plant is designed to eat them or if it happens by accident, the fact that it is big enough to do so is extraordinary. A Nepenthes captures prey by growing large cylindrical “pitcher” leaves that hold sweet smelling fluid. Unfortunately for anything attracted to it, this liquid is not nectar but full of digestive juices. There is little chance for escape, as the interior is coated with smooth wax, making it nearly impossible to gain footing. The motion of struggling animals activates glands that release more digestive enzymes, some of which are so powerful that small insects completely dissolve within hours.
Quite possibly the strangest plant I have ever seen, the Sundew, seems like it should be from some strange region of outer space rather than almost every continent on Earth. The plant captures prey with specialized tentacles sticking out of leaves that produce sticky mucilage. Insects attracted to the sweet mucilage soon become hopelessly entangled. Then, the weird stuff happens. The tentacles twist shut, grabbing the animal in a manner that reminds one of an octopus grabbing something out of the sea. This movement is among the fastest examples of thigmotropism, the same behavior exhibited by vines grasping to a host plant. (Note: the videos in this article are embedded directly from YouTube, so we at the Post cannot control the spelling. Obviously, “cornivorous” is not correct.)
This plant is similar to the Nepenthes in that it can grow quite large and uses a “pitcher” trapping method. However, instead of growing only in the Pacific islands, it can be found across North America (I did not find it reassuring to find that Sarracenia could be growing in my backyard).
In all seriousness, I am not really concerned about it in my yard. I am much more concerned that it is becoming less and less likely to be there, because it is a threatened species. Carnivorous plants in general are especially in jeopardy because, in addition to challenges like habitat loss that many endangered species face, they have unique problems because of their specialized nature. They thrive in areas of low nutrients, and the heavy use of fertilizer is completely changing their environments. Algae blooms and farm runoff have changed the composition of the soil and water that Sarracenia is accustomed to, while other plants, that would have otherwise never been able to survive near Sarracenia, are now crowding them out, and unfortunately, the Sarracenia can not eat them.
This California native is essentially an upside down pitcher plant with some unique twists (literally). It is aptly named, as its winding stalk and top strongly resemble the venomous snake. Bugs are drawn to the “head” of the plant, which is shaped slightly like a mushroom with a hole in the bottom. As they crawl in, they become disoriented by what appears to be exits but are really just translucent spots at the top where the sun shines through. Eventually, the bug works its way back to the “neck” of the plant, where inward pointing hairs make a one-way street for the creature (think of the spiked strip at car lots that lets vehicles in but not out). Finally, at the bottom of the neck, there is the “stomach” which has digestive enzymes.
Although this plant is similar in many ways to other pitcher plants, it is also quite unique. Rather than a swamp or bog, where most carnivorous plants live, it lives in a sandy land of droughts and floods. Rather than large pitchers with pools of water, it has small pitchers designed to keep water out. It lives in one of the most unique habitats in the world – the southwestern tip of Australia, where everything must be adaptable to survive — and it changes its look entirely though the different seasons of the year. It stays dormant in winter, when frosts and floods can occur. When it comes back to life in spring, it has normal photosynthesizing leaves. However, as the dry summer approaches, it produces a second type of leaf – a pitcher leaf. When insects fall in, they are forced down by inward pointing hairs, like in the neck of a Cobra Lily. The Cephalotus, Nepenthes, Sarracenia and Cobra Lily are all unrelated plants that developed a similar method of survival in very different places, a fact that makes one appreciate how effective the pitcher trap is.
One of the most common and adaptable types of carnivorous plants, the Bladderwort can live underwater or above ground. It works by creating a bean-shaped trap that maintains a pressurized vacuum, with small hairs at the mouth of the trap acting as triggers. When prey touch the hairs, it opens the trap, destroys the vacuum, and is sucked in. Some varieties of Bladderwort are known to live inside of pitcher plants, creating the hungriest symbiosis in the plant kingdom. The video above shows a Cane Toad tadpole with its tale stuck in the Bladderwort’s trap. According to the person who posted the video, the whole tadpole was eventually drawn in and ingested, and that plant singlehandedly captured hundreds of them over just a few days.
A few other notable Carnivorous plants
Butterwort: Also known as the flypaper plant, the Butterwort uses sticky leaves to trap fruit flies and other small insects. Buying one of these plants may be a better alternative to using flypaper in your home, because it ingests the bugs and cleans up after itself, rather than flypaper, which retains its collection of dead flies.
Waterwheel: The Waterwheel plant is the aquatic equivalent of the Venus flytrap. It is believed that they are closely related. It uses the same bear-trap mechanism to catch prey, except that it targets tadpoles and larvae rather than fully-grown insects. And you thought the flytrap was weird. If you click on the image to enlarge, you can see the flytrap-like traps arranged in a wheel around the plant stem.
Special thanks to Mike Wenzel Of Atlanta Botanical Gardens.