Attack of the killer tomatoes

Botanists at Kew discover the plant is carnivorous, with ability to trap insects

Vegetarians, look away now.


Potatoes and tomatoes make good eating but they may also have a vicious side that makes them deadly killers on a par with venus fly traps and pitcher plants.

They have been identified as among a host of plants thought to have been overlooked by botanists and explorers searching the world’s remotest regions for carnivorous species.

Researchers at Royal Botanical Gardens Kew now believe there are hundreds more plants that catch and eat insects and other small animals than they previously realised. Among them are species of petunia, ornamental tobacco plants, potatoes and tomatoes and shepherd’s purse, a relative of cabbages.

“Widely recognised carnivorous plants number some 650 and we estimate that another 325 or so are probable additions – so an increase of about 50 per cent,” said Dr Mike Fay, of Kew.

Researchers realised the plant world was more bloodthirsty than had been realised when they carried out an assessment of carnivorous plants to celebrate the bicentenary of Charles Darwin’s birth.

Darwin himself had been fascinated by carnivorous plants and conducted many experiments in which he fed them meat, and in 1875 his book on them, Insectivorous Plants, was published.

Dr Fay 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.

Pitcher plants and venus fly traps have specialist structures to kill and devour their prey but other plants are more subtle and rely on supplementing their usual diet by passive means.

Among them are plants such as ornamental tobaccos, and some species of potatoes and tomatoes which have sticky hairs which trap aphids and other small invertebrates. It is thought that rather than devour the prey directly the dead bodies decay slowly and the nutrients fall to the ground where they are taken up by the roots.

“They catch little aphids on the sticky hairs all the time. As these insects break down and drop to the ground the ground becomes enriched and the plants absorb them through the roots,” he said.

Such an ability is comparable to that of Roridula in Southern Africa which has sticky leaves on which flies get stuck but has no means of digesting them. It relies on a bug which devours the flies and the plant is then able to extract nutrients from the faeces which drop to the ground.

Domestic varieties of tomatoes and potatoes retain the ability to trap and kill small insects with their sticky hairs and are likely to absorb the nutrients through their roots when the animals decay and fall to the ground.

They are, however, thought to derive little benefit because they are so well-supplied with fertilisers whereas in the wild it might be an important source of food.

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.”

Shepherd’s purse is thought to be carnivorous, at least in part, because its seeds are covered in a thin layer of a substance that both attracts tiny organisms in the soil and kills them. Furthermore, the seeds secrete an enzyme which can break down the bodies so the nutrients can be taken up during germination.

Dr Fay said the study’s findings backed up the idea that all flowering plants began with the capacity to eat meat when they evolved but that only some of them made use of and retained the ability.

The researchers, publishing their finding in The Botanical Journal of the Linnean Society, added: “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.

“Overall, angiosperms [flowering plants] of many types may be involved in a degree of carnivory and be ‘proto-carnivorous’; perhaps we should be more curious about why more plant species have not developed a ‘taste’ for animal-derived nutrients.”

Blood-curdling tales of meat-eating plants have fascinated people in Britain ever since the first live venus flytrap to reach London caused a sensation across Europe in the 18th century.

Stories of man-eating specimens have held a particular attraction since featuring in such stories as The Day of the Triffids (1951) and The Little Shop of Horrors (1960) – more recently in the Harry Potter books, whose Venomous Tentacula tries to seize living prey with its grasping vines.

One 19th-century tale of a tree in Madagascar with tentacles that would grab hold of people and drag them to their doom even purported to be based on eyewitness accounts and was only discounted in the 20th century. Another reported a man-eating tree in Central America which would crush bodies with its tentacles “until every drop of blood is squeezed out of it and becomes absorbed by the gore-loving plant”.

The potato can only dream...

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Cabinet Maker / Joiner

£22000 - £24000 per annum: Recruitment Genius: This bespoke furniture and inte...

Recruitment Genius: Graphic and Motion Designer

Negotiable: Recruitment Genius: Do you get a buzz from thinking up new ideas a...

Recruitment Genius: Media Telesales Executive - OTE £25,000

£14500 - £16000 per annum: Recruitment Genius: This is an opportunity to join ...

Recruitment Genius: Female Care Worker

£7 - £8 per hour: Recruitment Genius: This expanding, vibrant charity which su...

Day In a Page

Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

The addictive nature of Diplomacy

Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

Fashion: Ooh, Lady Chatterley!

Take inspiration from DH Lawrence's racy tome with equally racy underwear
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

Charlie Austin: ‘If the move is not right, I’m not going’

After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea
Tunisia fears its Arab Spring could be reversed as the new regime becomes as intolerant of dissent as its predecessor

The Arab Spring reversed

Tunisian protesters fear that a new law will whitewash corrupt businessmen and officials, but they are finding that the new regime is becoming as intolerant of dissent as its predecessor
King Arthur: Legendary figure was real and lived most of his life in Strathclyde, academic claims

Academic claims King Arthur was real - and reveals where he lived

Dr Andrew Breeze says the legendary figure did exist – but was a general, not a king
Who is Oliver Bonas and how has he captured middle-class hearts?

Who is Oliver Bonas?

It's the first high-street store to pay its staff the living wage, and it saw out the recession in style
Earth has 'lost more than half its trees' since humans first started cutting them down

Axe-wielding Man fells half the world’s trees – leaving us just 422 each

However, the number of trees may be eight times higher than previously thought
60 years of Scalextric: Model cars are now stuffed with as much tech as real ones

60 years of Scalextric

Model cars are now stuffed with as much tech as real ones