What are
carnivorous plants?
From Darwin to suction traps: how plants evolved into predators, and what exactly makes them carnivorous
Plants that catch and eat insects, it sounds like something out of a horror movie, but carnivorous plants are one of the most fascinating groups in the plant kingdom. It was none other than Charles Darwin who, in 1875, was the first to scientifically prove that these plants are indeed carnivorous. Since then, more than 600 to 1000 species have been described, spread across multiple plant groups that independently developed the same strategy.
What makes a plant carnivorous?
Not every plant that happens to catch an insect is carnivorous. A rose on which a fly dies is not a carnivorous plant. To be considered truly carnivorous, a plant must meet three cumulative conditions:
This adaptation is no coincidence: carnivorous plants almost always grow on nutrient-poor, wet soils such as bogs, swamps, and rock faces with rainwater. Nitrogen and phosphorus are scarce in these environments, and by catching prey, they compensate for this deficiency.
Five trapping methods
Carnivorous plants have evolved independently multiple times, and this is reflected in the diversity of trapping mechanisms. There are five main types:
Leaves are covered with sticky, glue-like droplets that hold small insects as soon as they make contact. In some species, such as Drosera, the leaf can slowly wrap around the prey for better digestion. This is the most common trapping method in the carnivorous plant world.
Insects are attracted by color or scent and fall into a pitcher from which they cannot escape. In Sarracenia, downward-pointing hairs create this effect; in Nepenthes and Cephalotus, there is a large amount of digestive fluid in the pitcher. A persistent myth: the pitchers do not close themselves — they are always open.
Prey doesn't fall into the trap but walks into it voluntarily. Small translucent windows at the top of the trap disorient insects: they fly towards the light, but that's not the exit. Once inside, they become confused and sink deeper into the trap.
The most well-known and spectacular method. On each side of the leaf are three trigger hairs. If two hairs are touched within 20 seconds, the trap snaps shut. If there is indeed something inside, further movement stimulates the plant to fully close the trap and release digestive juices. This prevents the plant from wasting energy on things like raindrops.
The most ingenious method. Small underwater bladders are filled with air as the plant actively pumps out fluid — a negative pressure is created. As soon as prey touches a trigger hair, the trapdoor opens and the surrounding water with the prey is sucked in within milliseconds. Utricularia (bladderwort) also occurs in the Netherlands and Belgium, in the same areas as sundew.
Want to know more or get started yourself?
On our website, you'll find care tips per species and a fully grown assortment, from hardy Sarracenia to tropical Nepenthes.
Questions about carnivorous plants?
Whether you're just starting or have been growing for years, feel free to send a message to killian@dupontflora.com. We're happy to help you based on 15 years of our own growing experience.
0 comments