Killer Plants

A fly buzzes over a swamp and catches the sweet scent of nectar. Following the scent to its source, the fly lands on a bright-red leaf and—SNAP! It’s trapped between the leaves of a Venus flytrap. Over the next 5 to 12 days, the plant will digest its meal.

Why does the Venus flytrap do this? The swampy soil where it lives lacks important nutrients the plant needs in order to grow. That means it must turn to another source: insects.

A fly buzzes over a swamp. It notices the sweet smell of nectar. Following the scent to its source, it lands on a bright-red leaf. Suddenly—SNAP! The fly is trapped between the leaves of a Venus flytrap. Over the next several days, the plant will digest its meal.

Why does the Venus flytrap do this? It lives in swampy soil, which lacks nutrients the plant needs in order to grow. So the plant turns to another source: insects. 

The Venus flytrap is one of more than 800 known species of carnivorous plants. All carnivorous plants grow in places with nutrient-poor soil. Over millions of years, these plants developed adaptations that allow them to digest insects, spiders, and more. These prey provide the plants with the nutrients they need to grow.

British naturalist Charles Darwin was fascinated by carnivorous plants. He spent 16 years studying them before publishing his book Insectivorous Plants in 1875. “Darwin recognized that carnivorous plants were substituting animal prey for nutrients they would typically get from the soil,” says Thomas Givnish, a botanist at the University of Wisconsin.

Carnivorous plants are a perfect example of one of Darwin’s theories of evolution, called convergent evolution. In convergent evolution, similar environmental factors cause the same traits to evolve among unrelated ancestors. “Carnivorous plants have 10 separate origins,” says Givnish. At least one species of carnivorous plant can be found on every continent except Antarctica.

Venus flytraps are carnivorous, or meat-eating, plants. Over millions of years, they developed the ability to digest insects, spiders, and more. These prey provide important nutrients that the plants would normally get from the soil. There are more than 800 known species of carnivorous plants. 

The famous British scientist Charles Darwin was fascinated by carnivorous plants. He spent 16 years studying them and published a book about them in 1875. “Darwin recognized that carnivorous plants were substituting animal prey for nutrients they would typically get from the soil,” says Thomas Givnish. He’s a plant scientist at the University of Wisconsin.

Darwin is known for his theory of evolution. It describes how species change over time to better fit their environments. Carnivorous plants are a perfect example of this, says Givnish. At least 10 different types of plant that grow in nutrient-poor soil have evolved to eat insects. Now carnivorous plants can be found on every continent except Antarctica! 

Plants can’t move around like animal predators. Since they’re stuck in one place, carnivorous plants have sneaky adaptations to lure, trap, and digest prey.

Usually plants produce nectar to attract pollinators that will transport pollen from plant to plant so the plants can reproduce. But carnivorous plants use nectar to kill. An insect will land on a leaf expecting a meal . . . only to find it’s their last!

Plants can’t move around to hunt like animals can. So carnivorous plants use other tricks to snag their prey. They mostly grow in sunny and moist places where there are a lot of insects. The sunlight gives the plants energy to grow the traps they use to catch prey.

Most plants make nectar to attract pollinators. These insects carry pollen from plant to plant as they feed, helping the plants reproduce. But carnivorous plants use nectar to kill. Insects lands on a leaf expecting a meal . . . only to find it’s their last!

In the summer of 2017, student biologists made a surprising discovery in the jug of a pitcher plant in the bogs of the Algonquin Wildlife Research Station in Whitney, Canada. They found the gooey remains of a tiny salamander. Were these plants regularly snacking on salamanders? To find out, biologist Patrick Moldowan and his team monitored 144 plants. About 20 percent of them caught at least one salamander. It turns out that as these young salamanders emerge from the water, they sometimes fall into the plants’ traps.

“A salamander is a huge nutritional boom,” says Moldowan. An insect meal would be like eating a small salad, but a salamander is like a large steak dinner, he says.

In the summer of 2017, student biologists made a surprising discovery. They were studying pitcher plants in a bog in Whitney, Canada. They peered inside the jug of one pitcher plant. Inside were the gooey remains of a tiny salamander.

Were these plants regularly snacking on salamanders? Biologist Patrick Moldowan and his team decided to find out. They monitored 144 pitcher plants. About 20 percent of them caught at least one salamander. The young salamanders sometimes fall into the pitcher plants as they emerge from the water, the scientists found.

“A salamander is a huge nutritional boom,” says Moldowan. An insect meal would be like eating a small salad, he says. But a salamander is like a large steak dinner. 

Salamanders aren’t the weirdest things to be found digesting in a pitcher plant. Back in 2009, scientists discovered a pitcher plant in the Philippines that preys on rats. The following year, a plant was found in Borneo that gets most of its nutrients from the poop of tree shrews!

As strange as they are, carnivorous plants are just one example of wild and wacky things we can find in nature. “There are so many things waiting to be discovered in your backyard,” says Moldowan.

Salamanders aren’t the weirdest thing scientists have found in a pitcher plant. Back in 2009, scientists discovered a pitcher plant in the Philippines that preys on rats. The following year, an even weirder plant was found in Borneo. It gets most of its nutrients from the poop of tree shrews!

Carnivorous plants are spectacularly strange. But they’re just one example of wild and wacky things we can find in nature, says Moldowan. “There are so many things waiting to be discovered in your backyard.”