The Fascinating World of Carnivorous Plants

One of my favorite things about teaching for Nature Links is the way in which participants themselves take ownership over the curriculum. Our participants are as much in charge of what we learn as I am. Each season, they teach their own classes on topics that range from assistive technology to cheetahs to knitting to the impact of ocean plastic on orcas. And when they’re not teaching their own classes, they’re making lots of great suggestions about what we should learn next. I saw the coolest mushroom on my hike yesterday! Can we do a class on mushrooms? I’ve always wanted to go to Toronto. Can we travel there together on a virtual field trip? I always say yes, not only because they are great ideas but because often our very best classes come from topics I never would have thought of myself!

Our most recent participant suggestion was from Justin who asked if we could do a class on carnivorous plants. I have to be honest, my mind went directly to “Twoey”, a flytrap-like creature from Little Shop of Horrors. I didn’t know much about carnivorous plants before teaching the class, but that’s also one of the best parts of my job—I get to do research on fascinating aspects of nature to help our participants find out what they want to know. Carnivorous plants are, indeed, incredibly fascinating. Not only are they native to every continent except for Antarctica, but each species adapted its own unique mechanism for trapping and digesting prey. While we didn’t have time to dig into each one of the 600 or so species of carnivorous plants around the world, we had a great time exploring four of these captivating creatures…

The Venus Flytrap

We all agreed it would be silly not to begin with the Venus flytrap. It’s both the most recognizable of all carnivorous plants and one that’s native to North America. Most folks know that these amazing plants catch their prey by sensing an insect inside its lobed leaf and snapping shut, but most people assume the plant snaps immediately and indefinitely. In fact, the trapping mechanism on a Venus flytrap is much more complex than that. These plants don’t snap shut on first contact, so as to avoid wasting valuable resources on an errant leaf that might find itself fallen into its jaws. Instead, the plant senses first contact by a visitor and then waits about 20 seconds or so to confirm that a second contact has been made. It then snaps shut, trapping the insect inside. Special glands on the leaf surface secrete a red sap that helps it digest its meal. But these leaves only have the ability to snap shut about 6 times before they close permanently. Justin told us that in his opinion, the beauty of these plants is that they are so intelligent despite not having a brain. He feels that these creatures help remind us of the often surprising complexity of all living things on Earth, both big and small.

Butterwort

The next carnivorous plant on our list was butterwort. Like nearly all carnivorous plants, these plants are known to grow in locations with poor, acidic soil. They use the nutrients absorbed by insects to supplement their diets and thrive. The 80 or so different species of butterwort are known to sport a purple, white or blue flower. But hidden behind this alluring bright flower is a series of green or reddish leaves coated in a sweet and sticky nectar that helps attract small flies and gnats. According to folklore of Scotland and Wales, the plant was known to have magical properties that helped protect cows’ milk from evil, hence the name.

Sundew

One of our favorite plants to explore in this class was the sundew. These plants almost look like chenille stems gently covered in a morning dew. This image seems pretty inviting to a fly, bee or beetle, but the dewy drops are actually a sticky mucilage. When an insect touches one of these, it becomes trapped, and the plant reacts by rolling itself up around the insect. There are nearly 200 unique species of sundew and they can be found nearly all over the world. Charles Darwin was apparently pretty obsessed with this beautiful plant, once saying "…at the present moment, I care more about Drosera than the origin of all the species in the world.”

Pitcher Plants

The last type of carnivorous plant on our list is also possibly the most impressive. Pitcher plants make up a wide variety of species that live in a range of habitats, including rainforests, pine barrens and sandy coastal swamps. These guys attract their prey into a pitcher-shaped pitfall trap that usually contains intoxicating, sticky liquid inside that is used to disorient, drown and digest its prey. The largest of all pitcher plants is likely the Attenborough’s pitcher plant found in the Philippines. Although this plant is critically endangered, the largest have been known to grow to a massive 5 feet in height with a foot-wide pitcher, ready to trap not only insects but even frogs, birds and small rodents! After watching a video of a pitcher plant trapping a curious mouse, we had a great conversation in our group about the assumptions we often make culturally about mammals being more powerful or “smarter” than plants, and just how much the pitcher plant throws off this commonly held belief.

Thanks to Justin, we learned so much in our class about the Venus flytrap, the butterwort, the sundew and the pitcher plant. Keep checking back with us from time to time to hear updates on the fabulous class ideas our participants have chosen on our collective journey of curiosity. Our intelligent and curious participants will surely continue to lead us to some incredibly interesting places!