Nepenthes

Don't fall in...

Plants that eat meat. No really, some of them eat rats. Nepenthes are a type of carnivorous plant native to Southeast Asia, with the majority of them found on the island of Borneo, and they are bonkers. They generally consist of two parts, the lower ring of leaves and their traps are close to the ground with vines extending upwards and finding support on other plants. The traps at the end of the vines on the upper parts of the plant tend to look different from the ones on the ground. Why is that? Well, let’s talk about the traps.

Nepenthes are commonly known as pitcher plants or monkey cups. Monkey cups as a moniker is kind of inaccurate since it’s a little known species of ape, Homo sapiens, that have actually been documented using the dried out nepenthes traps to hold things, but I digress. As you can imagine from the common names, nepenthes traps are pitcher-shaped with a little lid extending over the opening to keep the rain out. The lip of the pitcher is ridged and slippery. Inside the pitcher, should an unwary insect wander on to the slippery ridge and fall in, is filled with bubbling digestive juices. (OK, they don’t bubble. Artistic license?) Nepenthes use a number of tactics, sweat smells, foul smells, coloration, shape, and morphology to trap insects and sometimes small reptiles, amphibians, birds, and mammals inside their pitchers. The pitchers at the bottom of the plant are different from the pitchers at the top because the prey they need to catch is different. This is called not putting all of your eggs in one basket. Very clever, these carnivorous plants.

What on EARTH, you might be wondering, would possess a plant to start drowning animals on the regular? It is for food, not for pleasure, not to worry. Nepenthes, like other carnivorous plants, live in environments where the soil is poor in nitrogen and phosphorus. As it happens, decaying critters are rich in nitrogen and phosphorus. Sort of a no-brainer from the nepenthes perspective I’d imagine. According to this article from the Smithsonian Magazine nepenthes, as well as many other carnivorous plants, repurposed enzymes already commonly found in, and used by, plants as they evolved their unique ability. Enzymes called Chitinases, the article states, break down the chitin found in insect exoskeletons, so are a useful part of the digestive soup at the bottom of a pitcher plant. But Chitinases are also a part of a non-carnivorous plant’s defense against fungi, which have chitin in their cell walls. Similarly, root enzymes that aid in absorption of nutrients are found in the leaves of carnivorous plants, enabling them to take nutrients in on the exact opposite end of the plant.

But there’s so much more than just clever evolution going on inside a pitcher plant. Apart from being murder pots, nepenthes also form symbiotic relationships with some animals. For example, N. bicalcarata has hollow tendrils that are home to carpenter ant colonies. Another example is Nepenthes lowii, which, as this article from the World Wildlife Foundation states, gives sweet nectar to shrews so they’ll poop in the trap. To each their own, I always say.

I also learned from that WWF article that the largest carnivorous plant in the world is named after David Attenborough, Nepenthes attenboroughii. Its pitchers are nearly a foot wide. Life. Goals.

I still have to tell you about the rat eater, N. rajah, which has pitchers that can hold up to three quarts of digestive liquid. I am not always great with things involving numbers, but I believe that’s almost a gallon. In a similar mutualism to the N. lowii and its mountain shrews, N. rajah feeds rats for their poop, sometimes the rats slip in and the plants are forced to digest them. C’est la vie.

While you picture rats drowning in a gallon of digestive juice produced by- a plant, keep this in mind as well. In 1737 Carl Linnaeus published an article about the plant under the name nepenthes for the first time. The name is in reference to the drug nepenthes pharmakon from Homer’s Oddyssey. Nepenthes means ‘without grief’ and the drug was said to cause forgetfulness, taking away sorrow. Linneaus explained that the plant was so wondrous that one would forget all past ills upon seeing it. Not to be morbid, but one has to imagine that drowning would also have the same effect, Carl.