When you hear the term ‘Carnivorous’, if you are anything like me, you imagine not merely a meat eater, but perhaps even a flesh eating creature, hell, a man eater. But in the case of plants, a carnivorous plant, simply eats insects and other anthropods. The plants have adapted to life in areas where the soil is thin, or poor in nutrition, but where there is ample light. They are structurally designed to capture their prey in order to survive, and absorb the necessary nutrients from that prey, to thrive. Carnivorous plants derive most of their nutrients from eating animals they have trapped within their plant structure, an adaptation due to the environment in which they are found. Charles Darwin wrote the first literature on this plant type, ‘Insectivorous Plants’, in 1875.
There are at least 583 species of carnivorous plants that trap and kill their prey, each displaying one of the 5 different trapping mechanisms;
- Pitfall traps.
- Flypaper traps.
- Snap traps.
- Bladder traps.
- Lobster pots (aka eel traps).
Pitfall Traps: generally trap their prey within a rolled leaf structure which contains a pool of digestive enzymes at the base. They are a passive trap, attracting prey with nectar secretions. The pitcher plant uses this trapping mechanism. The inside of the pitcher plant is covered in a slippery wax, which causes the insects to fall into the pitcher. Once inside, the digestive enzymes and bacteria begin to break down the prey so that the plant can begin to absorb it.
Like most of the plants within the pineapple family, the Bromeliad Brocchinia Reducta has a tightly packed spiral of waxy leaves that form somewhat of a cup. Water collects in this cup and often provides a habitat for frogs and insects, however in this case, the cup turns into a specialised insect trap.
Flypaper Traps: use a sticky mucilage, like glue. The leaves have mucilage secreting glands, but also a rapidly responsive leaf surface with responds to the prey; rolling the leaf blade to prevent the insect being washed away by rain, or the leaf creating a dish like surface underneath the prey to form a shallow digestive pit.
Snap Traps: The most well known snap trap is the Venus Flytrap (Dionaea Muscipula). The trapping mechanism has sometimes been described as a mouse trap/bear trap or man trap referring to the speed of movement and the shape.
The Snap Trap is an active trap as it used rapid movement in order to trap it’s prey. Snap traps have fine hairs inside the lobes which are sensitive to touch. They also have a hinge -like mechanism along the midrib, which changes in shape, and is caused to quickly slam shut when the hairs are triggered. The process takes less than 1 second!
Bladder Traps: pump ions out of their interiors, with water following which creates a partial vacuum inside of the bladder. At the opening of the bladder sits a small opening/door which has a pair of long trigger hairs. When the hairs are touched, the door is opened and the invertebrae is sucked in.
Lobster Pot Traps: have a chamber that is easy to enter, but extremely difficult to exit because the exit is either hard to find obstructed.
There is a great variety of carnivorous plants available that can be grown in your gardens, and they make an interesting addition to arrangements too, undoubtedly due to their unique shapes, and colourings. Experiment with these delightful plants for something fun, new and interesting- you are sure to create a talking point at least!