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
PROMOTED VIDEO
Life and Style
life
Arts and Entertainment
Cold case: Aaron McCusker and Christopher Eccleston in ‘Fortitude’
tvReview: Sky Atlantic's ambitious new series Fortitude has begun with a feature-length special
Voices
Three people wearing masks depicting Ed Miliband, David Cameron and Nick Clegg
voicesPolitics is in the gutter – but there is an alternative, says Nigel Farage
Voices
The veterans Mark Hayward, Hugh Thompson and Sean Staines (back) with Grayson Perry (front left) and Evgeny Lebedev
charity appealMaverick artist Grayson Perry backs our campaign
News
i100
News
people
ebooks
ebooksA special investigation by Andy McSmith
Sport
Chelsea manager Jose Mourinho
footballThe more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him
Life and Style
Vote green: Benoit Berenger at The Duke of Cambridge in London's Islington
food + drinkBanishes thoughts of soggy school dinners and turn over a new leaf
News
Joel Grey (left) poses next to a poster featuring his character in the film
peopleActor Joel Grey comes out at 82
News
i100
News
business
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

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

iJobs Job Widget
iJobs General

Ashdown Group: Marketing & Sales Manager

£40000 per annum: Ashdown Group: A reputable organisation within the leisure i...

Tradewind Recruitment: Science Teacher

£90 - £140 per day: Tradewind Recruitment: I am currently working in partnersh...

Recruitment Genius: Doctors - Dubai - High "Tax Free" Earnings

£96000 - £200000 per annum: Recruitment Genius: Looking for a better earning p...

Recruitment Genius: PHP Developer

£32000 - £36000 per annum: Recruitment Genius: A rapidly expanding company in ...

Day In a Page

Isis hostage crisis: The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power

Isis hostage crisis

The prisoner swap has only one purpose for the militants - recognition its Islamic State exists and that foreign nations acknowledge its power, says Robert Fisk
Missing salvage expert who found $50m of sunken treasure before disappearing, tracked down at last

The runaway buccaneers and the ship full of gold

Salvage expert Tommy Thompson found sunken treasure worth millions. Then he vanished... until now
Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Homeless Veterans appeal: ‘If you’re hard on the world you are hard on yourself’

Maverick artist Grayson Perry backs our campaign
Assisted Dying Bill: I want to be able to decide about my own death - I want to have control of my life

Assisted Dying Bill: 'I want control of my life'

This week the Assisted Dying Bill is debated in the Lords. Virginia Ironside, who has already made plans for her own self-deliverance, argues that it's time we allowed people a humane, compassionate death
Move over, kale - cabbage is the new rising star

Cabbage is king again

Sophie Morris banishes thoughts of soggy school dinners and turns over a new leaf
11 best winter skin treats

Give your moisturiser a helping hand: 11 best winter skin treats

Get an extra boost of nourishment from one of these hard-working products
Paul Scholes column: The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him

Paul Scholes column

The more Jose Mourinho attempts to influence match officials, the more they are likely to ignore him
Frank Warren column: No cigar, but pots of money: here come the Cubans

Frank Warren's Ringside

No cigar, but pots of money: here come the Cubans
Isis hostage crisis: Militant group stands strong as its numerous enemies fail to find a common plan to defeat it

Isis stands strong as its numerous enemies fail to find a common plan to defeat it

The jihadis are being squeezed militarily and economically, but there is no sign of an implosion, says Patrick Cockburn
Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action

Virtual reality: Seeing is believing

Virtual reality thrusts viewers into the frontline of global events - and puts film-goers at the heart of the action
Homeless Veterans appeal: MP says Coalition ‘not doing enough’

Homeless Veterans appeal

MP says Coalition ‘not doing enough’ to help
Larry David, Steve Coogan and other comedians share stories of depression in new documentary

Comedians share stories of depression

The director of the new documentary, Kevin Pollak, tells Jessica Barrett how he got them to talk
Has The Archers lost the plot with it's spicy storylines?

Has The Archers lost the plot?

A growing number of listeners are voicing their discontent over the rural soap's spicy storylines; so loudly that even the BBC's director-general seems worried, says Simon Kelner
English Heritage adds 14 post-war office buildings to its protected lists

14 office buildings added to protected lists

Christopher Beanland explores the underrated appeal of these palaces of pen-pushing
Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Human skull discovery in Israel proves humans lived side-by-side with Neanderthals

Scientists unearthed the cranial fragments from Manot Cave in West Galilee