Smartest Plant Revealed in New Study

The carnivorous pitcher plant might be the world's smartest plant. According to a new study, the plant knows the best ways to feast and it does so without the help of a brain.

In this study, the researchers examined how a specific species of the pitcher plant known as the Nepenthes rafflesian found in Borneo, consumed food. The plant eats via its leaves that form into a pitcher-like shape. During days when the rim of the pitcher gets wet, ants easily slip into the pitcher. On dry days, however, the pitcher is not as slippery. On these days, individual ants can walk along the leaves and collect sweet nectar.

"The plant's key trapping surface is extremely slippery when wet, but not when dry," explained project leader Ulrike Bauer of Bristol University's School of Biological Sciences. "For up to eight hours during dry days, these traps are 'switched off' and do not capture any of their insect visitors. At first sight, this is puzzling because natural selection should favor traps that catch as many insects as possible."

However, the researchers found that once these ants become aware of the nectar, being social insects, they typically go back and inform their colonies. When a bunch of ants return to get the nectar, the plant adjusts and traps the ants by making their leaves slippery.

"By 'switching off' their traps for part of the day, pitcher plants ensure that scout ants can return safely to the colony and recruit nest-mates to the trap," Bauer said according to Discovery News. "Later, when the pitcher becomes wet, these followers get caught in one sweep. What looks like a disadvantage at first sight, turns out to be a clever strategy to exploit the recruitment behavior of social insects.

The team found that the plant could control the slipperiness of its leaves by secreting the sugary nectar. Once the nectar is secreted and the surface becomes wet from condensation, the ants become trapped with nowhere to go but into the plant.

"Of course a plant is not clever in the human sense - it cannot plot. However, natural selection is very relentless and will only reward the most successful strategies," Dr. Bauer commented according to ABC Science. "What superficially looks like an arms race between nectar robbers and deadly predators could in fact be a sophisticated case of mutual benefit. What superficially looks like an arms race between nectar robbers and deadly predators could in fact be a sophisticated case of mutual benefit."

The study was published in the journal, Proceedings of the Royal Society B.