What makes a plant a killer?
There are more than 800 recognised species of carnivorous plants. They can be found in 11 different plant families and vary widely in appearance and size. The only thing they all have in common: THE NEED TO KILL.
To be defined as carnivorous, a plant must first have a trait that is specifically for the attraction, capture and digestion of prey. The second requirement is the ability to absorb nutrients from dead prey and gain an advantage from the integration of these nutrients.
Unlike other plants that get their nutrients from the soil and by forming sugars through photosynthesis, carnivorous plants have evolved to get theirs from insects. Amazingly, they have adapted to grow in places where the soil is thin or low in nutrients, especially nitrogen.
While death and dinner are the same for all carnivorous plants, keep reading below to learn about the different tactics they use to lure, trap and trick their prey.
Snap traps – fast and furious
This is perhaps the most well-known trapping mechanism of carnivorous plants, made famous by the Venus Flytrap (Dionaea muscipula). This trapping technique has also been described as a ‘mouse trap’, ‘bear trap’ or ‘man trap’, due to its shape and rapid movement.
It has leaves with a terminal section divided by two lobes, hinged along the midrib. Inside are trigger hairs and when two are bent by a visiting insect within 20 seconds, the trap snaps shut. While the mechanism of how exactly this happens is still debated, the whole process takes less than a second for a Venus Flytrap.
Further stimulation of the trigger hairs by the struggling victim then causes the lobes to close even tighter. This forms a kind of stomach, activating digestive enzymes so digestion can take place over a period of one to two weeks.