Long trichomes scattered on the upper leaf blade are very sensitive to touch, and when two or more are triggered by a moving animal, the bivalved structure of this Venus flytrap, Dionaea muscipula (Family Droseraceae), will close. Long trichomes scattered on the upper leaf blade are very sensitive to touch, and when two or more are triggered by a moving animal, the bivalved structure of this Venus flytrap, Dionaea muscipula (Family Droseraceae), will close.