Easily the most intriguing thing I read in the last 24 hours was the massive sheep-eating plant about to flower in the UK. Called Puya Chilensis, this plant sounded so much better than a venus flytrap. I needed to know more but now that I do, I’m thinking the BBC, Huffington Post and others have likely served up a dud.
The story surfaced on Tuesday when Britain’s Royal Horticultural Society’s media centre put out a gem of a press release. Their South American plant puya chilensis was about to flower for the first time in 15 years. The plant, they said, lived in the wild on the fertiliser provided by dead animals, including sheep, which decomposed trapped in its thick spines.
For the RHA this was a “gruesome secret” where dead animals become the “grizzly (sic) equivalent of a bag of fertiliser”. This is a big claim for a garden in the green heart of Surrey and sheep are big animals to get stuck in bushes. Yet the tale was too enticing to media eager for an off-beat story, and in a great setting. RHS Garden Wisley is so much a flagship of the Royal Horticultural Society it even sounds like one. There, irises and candelabra primulas line the long ponds, roses and salvias sway in the Country Garden, and glorious peonies dazzle and bloom. But does something more sinister live in this part of England’s green and pleasant land?
Puya chilensis is a hardy plant surviving on mostly waterless hills in Chile. It is a terrestrial bromeliad, which means it has one seed-leaf not two and is a cousin of the pineapple. Puya chilensis is common enough in the Mattoral region. However because the Mattoral also contains Chile’s largest cities including Santiago, the constant land-clearing and the plant’s high flammability is making it rare.
What’s also rare, says the RHA, is the striking flowering of puya chilensis. It produces enormous spikes of neon bright, greeny-yellow flowers. The blossoms are gigantic. Individual blooms measure 5cm and they contain enough nectar for a person to drink. Wisley is particularly delighted as it said few UK specimens have flowered, a fact the nursery puts down to difficulties in replicating its natural diet in Chile.
Yet on the Scilly island of Tresco, the Abbey Garden’s puya chilensis has been thriving since 1848 and flowers annually. “Each spring the clumps of puyas send up great spikes of flowers 2-3m high, the flowers clustered at the top,” the garden’s website said. “The actual flowerhead is about 1m long and packed with racemes of chunky flowers, the sterile tips of which stick out, affording a perch for thirsty birds.” There is no mention of puya’s taste for animals, something you’d think the Tresco gardeners would have noticed in 160 years.
The RHA say puya chilensis uses its razor-sharp hook-like spines to ensnare prey. The animals starve to death and decompose. Finally, after perhaps years, the plant feeds off the fertiliser. Chilean shepherds on the Matorral, they claim, are all too aware of the danger and they usually burn the plant when they see it. Because of the “problematic” food, Wisley feed their puya chilensis with a liquid fertiliser rather than sacrifice a sheep or two.
On the carnivorous plants UK forum, no-one had heard of this strange diet of the bromeliad. “Osmosis” raised the topic on the forum about speculation the plant may derive an advantage from the decaying carcasses of animals it snares in the wild. “I know this is not strictly carnivory,” Osmosis went on, “but with only a slight embellishment it makes a sensational answer to what is the largest carnivorous plant.” Another forum user, “vraev”, made the point carnivory was no longer such a big deal. “It seems almost one plant or another is trying to take advantage of the vast reservoir of animal nutrients,” he/she said.
I’m no botanist but I could find no evidence of carnivorous bromeliads either in scholarly publications or from talking to scientists who work in the field. In fact there is no evidence at all, earlier than the RHA media release of June 18. It is possible this is new science but I’ve not seen any papers. I asked the RHA “if this information has only recently came to light and if so, how?” They have yet to answer my query. The Beeb and Huffpo may have oversold puya chilensis but it doesn’t need to be sheep-eating to be an extraordinary creation of nature.
UPDATE: June 26, 2013. I got this response overnight from Stephanie Shepherd, Senior Press Officer, Art and Gardens:
Thanks for getting in touch. You can find references to the idea that the Puya chilensis derives a benefit from nutrients that leech into the soil from the decomposing carcasses of small animals (particularly farmed sheep) that become caught in its spines in Sharp Gardening by Christopher Holliday and in Maberley’s Plant-book. A Portable Dictionary of Plants, their Classifications, and Uses. 3rd Edition by David J. Mabberley. It has also been referenced by the National Botanic Garden of Wales, The Eden Project and BBC Wildlife Magazine and you can find a piece from Tresco here which references the plant’s reputation for snaring sheep. All of these pre-date the press release announcing the flowering of our Puya chilensis.
As you could probably tell from the tone in which the press release was written, the story was intended as quite a light hearted one and a way of drawing the attention of the wider public to some of the fascinating and peculiar plants that live in our world.