Venus Flytrap - Dionaea muscipula
 
Venus Fly Traps are by far the most commonly recognized and cultivated carnivorous plant. They are sometimes even sold as houseplants. Collectors have developed many different cultivars or genetic mutations which are raised for commercial markets. Variations may include leaf colour, trap colour, leaf length or thickness, trap size or shape, teeth sizes or growth habit.
 
The original Venus Fly Trap is native to the bogs and swamplands of North and South Carolina where it gains extra minerals and nutrients by catching and digesting insects. The trapping mechanism is simply a modified leaf composed of two lobes hinged together by a midrib. The upper surface of these lobes contains red pigments called anthocyanin which serve to attract insects.
 
The trap mechanism is tripped when prey contacts one of the three "hairs" on the upper surface of each of the lobes. The mechanism is so specialized that it can distinguish between living prey and non-prey stimuli such as falling raindrops. To achieve this two trigger hairs must be touched within 20 seconds of each other or one hair touched twice in rapid succession before the lobes rapidly snap shut.
 
The edges of the lobes are fringed by stiff hair-like protrusions or cilia. When the trap is sprung these mesh together and prevent large prey from escaping. In a further specialism the gaps left between these "teeth" allow small prey to escape as the benefit that would be obtained would be less than the cost of digesting them. After digesting its prey a trap withers and dies and is of no use to the plant again. If the prey is too small and escapes, the trap will reopen within 12 hours and is ready to catch something else. If the prey moves around in the trap, it tightens and digestion begins more quickly. Once trapped the insect is digested by strong digestive enzymes a process that can take up to 10 days.
 
 
Venus Flytrap showing three trigger hairs
Venus Flytrap showing three trigger hairs
Venus Flytrap showing three trigger hairs
Venus Flytrap particularly red variant
Venus Flytrap
Venus Flytrap
Venus Flytrap
Venus Flytrap closed
Venus Flytrap showing modified leaf structure