Although there are about 625 species of carnivorous plants it is possible to categorize them in two ways for the sake of convenience. One way is to segregate those plants that are ‘active’. Such plants take certain specific action in order to hunt the prey – making them hunters in the true sense of the word. The remaining carnivorous plants can be called ‘passive’. They do not take any specific action but wait for the prey to walk into their ‘mouths’. Another way of categorizing carnivorous plants is to divide them in five categories as under on the basis of their preying styles:
- Plants having a pit-like arrangement into which the unwary prey falls. The main plants of this category are various species known as pitcher plant.
- The second category of insectivorous plants is known as sundew plants. They can be compared with fly-paper because they secrete sticky dew-like substance to attract and trap the insects.
- The third category comprises of plants known as Venus’s fly-trap (photo, above). Their leaves have hinge-like mechanism by which the opposite helves of the leaf come together to shut the victim inside.
- One more category of plants is known as bladderwort. The leaves of such plants have small bladders into which the insects and worms are sucked by vacuum action.
- Finally, there is a large group of carnivorous bog plants known as butterwort. These plants do not lay spring action trap like the Venus’s fly-trap but two sides of whose leaf roll around the insect imprisoning it.