Venus flytrap trap - HD 影片檔

"Close-up of the trap of a Venus flytrap (Dionaea muscipula). The Venus flytrap is a carnivorous plant that catches prey in a snapping trap formed from a highly-modified leaf. The end of the leaf is divided into two halves, fringed with stiff spikes. The inner portion of the trap has a red colour and secretes a mucilage that is attractive to flies and other insects. The surface of each half of the trap bears three touch-sensitive hairs. The trap is triggered when two of these hairs are touched within about twenty seconds. This failsafe mechanism prevents the trap from closing in error, for instance due to a raindrop. Once triggered, the trap snaps shut, quickly enclosing its prey and gradually tightening to form a seal. The trap then secretes digestive enzymes that consume the soft parts of the prey, providing the plant with nutrients, which are scarce in the wetland soils in which it evolved. The trap reopens after several days, and the desiccated husk is blown away."