Botanists have discovered for the first time that the plants are carnivorous predators who kill insects in order to “self-fertilise” themselves. Garden vegetables such as tomatoes and potatoes have been found to be deadly killers on a par with Venus fly traps, according to research.
New research shows that they capture and kill small insects with sticky hairs on their stems and then absorb nutrients through their roots when the animals decay and fall to the ground.
It is thought that the technique was developed in the wild in order to supplement the nutrients in poor quality soil – but even domestic varieties grown in your vegetable patch retain the ability.
The killer plants have been identified as among a host of species that are thought to have been overlooked by botanists and explorers searching the world’s remotest regions for carnivorous species.
The number of carnivorous plants is thought to have been underestimated by up to 50 per cent and many of them have until now been regarded as among the most benign of plants.
Among them are species of petunia, ornamental tobacco plants, some varieties of potatoes and tomatoes, and shepherd’s purse, a relative of cabbages.
Researchers at Royal Botanical Gardens Kew, which carried out the study, now believe there are hundreds more killer plants than previously realised.
Professor Mark Chase, of Kew and Queen Mary, University of London, said: “The cultivated tomatoes and potatoes still have the hairs. Tomatoes in particular are covered with these sticky hairs. They do trap small insects on a regular basis. They do kill insects.
“We suspect in the domesticated varieties they are getting plenty of food through the roots from us so don’t get much benefit from trapping insects. In the wild they could be functioning in the way that could properly be considered carnivorous.”
The study said it is likely that the meat-eating qualities of many plants has gone unrecognised because they are missing some of the prime characteristics associated with carnivorous species.
The researchers, publishing their finding in the ‘Botanical Journal of the Linnean Society’, said: “We may be surrounded by many more murderous plants than we think.
“We are accustomed to think of plants as being immobile and harmless, and there is something deeply unnerving about the thought of carnivorous plants,” they added.