In a historical letter dated Jan. 24, 1760, Arthur Dobbs, then Governor of North Carolina, wrote, " ...But the great wonder of the vegetable kingdom is a very curious unknown species of sensitive; it is a dwarf plant; the leaves are like a narrow segment of a sphere, consisting of two parts, like the cap of a spring purse, the concave part outward, each of which falls back with indented edges (like an iron spring fox trap); upon anything touching the leaves, or falling between them, they instantly close like a spring trap, and confine any insect or anything that falls between them; it bears a white flower; to this surprising plant I have given the name of Fly Trap Sensitive."

Description

The Venus flytrap uses a snap trap (sometimes referred to as steel trap), the most advanced trap mechanism to be found among carnivorous plants. The plant forms a rosette of leaves emerging from a short white rhizome (underground stem) with fibrous roots. The leaves, which can grow up to 10cm, are of two parts: a flat petiole (leaf stem) and a leaf blade modified into a trap.

The trap portion consists of two semicircular lobes united along the midrib of the leaf blade. Around the margin of each lobe grow stiff, spine-like guard hairs (15 to 20 along each margin), which mesh together when the trap closes to prevent the prey's escape. Along the inner edge of each lobe just below these marginal spines runs a narrow band of nectar glands which secrete sugary substance to attract potential prey. Much of the inner lobe below is crowded with numerous digestive glands, which often give the trap surface a bright-red coloration. Each inner lobe surface has three -- sometimes 4 or more -- fine bristles located in a triangular pattern. These are trigger hairs, which are sensitive to physical stimulation and, when properly stimulated, initiate a rapid trap closure.

Prey Capture

When an unwary insect brushes these hairs, the trap snaps shut, usually in less than half a second. The guard hairs of each lobe mesh together to prevent the insect's escape, and the prey is hopelessly confined between the two lobes. The insect's effort to free itself further irritates the trigger hairs, causing the lobes to close more tightly. This pressure sometimes crushes a soft-bodied insect. In several hours, as the lobes are tightly sealed, the trap becomes filled with digestive fluids secreted from the glands on the lobe surface, and the captured prey begins to dissolve. The trap remains closed during the digestive process which lasts for a week to ten days depending on the size of the prey. After the nutrients of the insect body are absorbed by the plant, the trap opens slowly. Inside the now dry trap is the remains of the hard shell part of the consumed insect. Wind and rain clean the lobes and the trap is ready again for another meal. A single trap is usually capable of repeating this process only three times or so during the life of the trap. After that it becomes insensitive to stimulation and dies, but new trap leaves are continuously sprouting out from the rosette center during the growing season of spring through summer.

When a trigger hair is stimulated by a piece of wood, or a finger, the trap also snaps shut. In this case, however, the trap opens the next day, since the plant does not find any nutritious object inside the trap.

The Venus flytrap (Dionaea muscipula) is endemic to the Atlantic coastal plain of North America, where it is highly localized to southeastern North Carolina and the adjacent northeastern part of South Carolina,  within a 100km radius around the city of Wilmington on the N.C. coast.

The Venus flytrap (Dionaea muscipula) is endemic to the Atlantic coastal plain of North America, where it is highly localized to

The Venus flytrap (Dionaea muscipula) is endemic to the Atlantic coastal plain of North America, where it is highly localized to s

The Venus flytrap (Dionaea muscipula) is endemic to the Atlantic coastal plain of North America, where it is highly localized to

The Venus flytrap (Dionaea muscipula) is endemic to the Atlantic coastal plain of North America, where it is highly localized to s