Green Predators: Carnivorous Plants

Meal Time for Plants 

Almost all plants photosynthesize, which means they make their own food by taking sunlight, as well as carbon dioxide from the air, to make sugars. However, plants and animals cannot survive on sugar alone, as your parents might have mentioned to you! All living beings also need nutrients. Some nutrients are common to hear about or read on nutrition labels of foods:  iron, potassium, magnesium, and calcium. Plants and animals need nutrients to help their systems run properly. Humans and other animals get nutrients from the food they eat. You may have heard some foods have more nutrients than others – “A salad is more nutritious than a gummy worm”. Plants usually find their nutrients in the soil they grow in, which they take up through their roots. 

What happens when a plant is growing in an area where there isn’t enough nutrients in the soil? This is where carnivorous plants come in! They have evolved different ways to eat insects and sometimes even frogs, salamanders, or mice. Let’s explore a few species of carnivorous plants we can find in the Biosphere.

Bladderwort

Bladderworts are the fastest predator in the world! These plants float in the water, but they do not capture their prey by swimming around. They have many little bladders which catch their underwater prey (see picture below). They look like little spheres all along the thin underwater leaves. Do you ever clean the house by vacuuming? You can think of the bladders as little vacuum traps. When an underwater insect swims by the bladder, the bladder sucks the insect in with up to 600G of force in less than a millisecond. That would be 6 times the force of a high speed race car crash before you can finish a single blink!

Like all of our other carnivorous plants, bladderworts produce flowers. Many species in the Biosphere have a beautiful bright yellow flower, but one has a small and elegant pink flower. These flowers have long stalks, keeping them high above the water so any pollinators passing by can see them.

Pitcher Plant

Pitcher plants are one of the coolest looking carnivorous plants around. They have evolved their leaves into a cup (pitcher) shape, where they hold a liquid which traps insects, frogs, salamanders, and even mice. But how exactly do they attract anything into the pitcher? 

At the beginning of the growing season, the plant releases sweet smells, attracting insects which are looking for nectar. These insects fly into the pitchers and get trapped in the liquid. The pitchers have tiny hairs on their walls which face down, stopping any insect from flying or climbing out. After quite a few prey have made their way into the pitcher, a rotten smell takes over, which attracts other types of insects and animals. This smell is released by the plant, but also has help from the decaying insects inside. The side of the pitchers also look like decomposing flesh, which also attracts certain animals.

Sundew

Sundews are also known as flypaper traps. Insects will land on their sticky hairs. Once the plant feels an insect trapped and squirming, the leaf will close around it and secrete a liquid. This liquid dissolves the inside of the insect, which the plant then absorbs. The only thing left will be the insect’s exoskeleton, which will eventually blow away in the wind. 

There are many species of sundew. The ones in the Biosphere have slightly different shapes. They can look completely round, spatula shaped, or even more paddle shaped. Can you notice the differences in leaf shape between the two pictures above?

Activity Time! 

These carnivorous plants have evolved so many cool ways to capture their prey. Can you come up with your own carnivorous plant trap?

If you were a plant, how would you capture your food?

Sketch out your idea!