Plantwatch: why does a rainforest vine turn into a part-time carnivore?

Scientists have finally discovered why this remarkable plant becomes hungry for bugs

It sounds like a science fiction horror movie - a carnivorous plant that grows up to 60 metres high reaching up through the canopies of tropical trees, feasting on bugs using sticky leaf glands that ooze digestive enzymes to absorb its catch of prey.

Triphyophyllum peltatum is a woody vine that grows in the rainforests of west Africa, although strangely it is a part-time carnivore that develops into a killer only at certain times. What turns this seemingly ordinary plant into a carnivore has been a mystery, largely because the plant is rare and difficult to cultivate.