There is an elite group of plants that rely not just on sun and rain for sustenance, but also the bodies of unsuspecting insects. The Venus flytrap is probably the most famous of the bunch, but it may be outdone by the predator plant in the video above. The Drosera glanduligera uses touch-sensitive tentacles to catapult insects into its digestive "mouth." Scientists observing the plant note that these hair-trigger tentacles are some of the fastest trapping mechanisms in the plant kingdom.
In a study published in the journal PLoS One, a group of German scientists used high-speed cameras to observe D. glanduligera in action. Plants are not generally known for their quick movements, so researchers were intrigued by the lightning-fast tentacles they saw.
D. glanduligera uses a two-step process for trapping prey. The outer tentacles flip an insect onto sticky inner tentacles that slowly draw its prey towards a digestive concavity. Enzymes in the concavity digest the insect into nutrients for the plant.
How exactly the outer tentacles work is a bit of a mystery. Plants do not have muscles, but scientists theorize that water movement within the plant causes some cells to swell with water and others to contract, a sort of hydraulic mechanism that results in the catapulting seen above. Each tentacle can only flip once, but D. glanduligera is an annual plant, and regrowing leaves is a small price to pay for a tasty meal.
Researchers observed that the tentacles take just 400 milliseconds to sense an insect and flip it onto its sticky leaves, where the bug has no chance of escaping. The two-part system is also more complex than other carnivorous plants - most of which rely on sticky leaves or hidden reservoirs of liquid to trap insects. In describing D. glanduligera's technique, scientists write it is "more accurately termed a catapult-flypaper-trap."