Flesh-eating plant traps worms with sticky underground leaves
To find Philcoxia’s grisly secret, Caio Pereira had to look underground. The plant biologist from Unicamp, Brazil, found that the plant traps and digests tiny worms with sticky underground leaves.
Plants have evolved to eat animals at least six times, and over 600 species of them now do so. They catch their prey with slippery water-filled pitchers, fast-snapping traps, sticky leaves and sucking bladders. Their strategies are diverse, but they all tend to grow in areas that are poor in nutrients. For example, familiar species like the Venus’ fly trap and the sundew live in bogs and swamps. In such inhospitable environments, these plants supplement their supplies of nitrogen, phosphorus, and other nutrients by feasting on the flesh of animals.
Philcoxia is no different. When Peter Taylor described the plants in 2000, he noted that they have several features that resemble those of other meat-eating species. Its mountain home is poor in nutrients and frequently starved of rain. Its roots are unusually sparse and lack the fungal partners that help other plants to survive. And it has tiny underground leaves – just a millimetre wide and coated with sticky glands, of the type found in other carnivorous plants.
There was just one problem. There were no signs of captured animals, or bodies nearby. If Philcoxia ate animals, it wasn’t doing so obviously. In 2007, Peter Fritsch found a possible answer. He noticed nematode worms stuck to the underground leaves, and reasoned that the plant was trapping and digesting them. Pereira, working with Fritsch, has now confirmed this hypothesis.
He found that Philcoxia’s underground leaves are littered with the bodies of dead nematodes. To check that the deaths aren’t coincidental, Pereira bred nematodes so that their bodies were full of nitrogen-15 – a rare and heavier-than-usual version of the element. He then “fed” the nematodes to Philcoxia. Two days later, Pereira found that 15 percent of the nitrogen-15 in the worms has been incorporated into the plant’s leaves. It was clear proof that Philcoxia was digesting the nematodes and absorbing the remains into their bodies.
Many meat-eating plants digest their prey with high concentrations of enzymes called phosphatases. Philcoxia does so too. Pereira found loads of the enzymes on Philcoxia’s leaves, which means that the plants are probably digesting the nematodes directly.
Pereira still wants to find out how Philcoxia lures its prey towards its traps. But for the moment, he has shown that its diet of worms greatly raises the level of nitrogen in its leaves, boosting it even above the levels of neighbouring plants that aren’t carnivorous.
That’s interesting, because some scientists have suggested that eating animals is a relatively inefficient way of coping with nutrient-poor environments. This would explain why carnivorous plants are relatively rare. But Philcoxia clearly shows that a fleshy menu can provide more nutrients the strategies of other plants in the same conditions.
Indeed, Philcoxia’s murderous habits suggest that we may have underestimated the true number of meat-eating plants in the world. After all, if this rare species feeds on microscopic prey using hidden traps, perhaps other plants do so too. As Mark Chase wrote a few years back, “we may be surrounded by many more murderous plants than we think”.
Reference: Pereira, Almenara, Winter, Fritsch, Lambers & Oliveira. 2011. Underground leaves of Philcoxia trap and digest nematodes. PNAS http://dx.doi.org/10.1073/pnas.1114199109
More on meat-eating plants:
- Flesh-eating plant inspires super-slippery material that repels everything
- Venus flytrap FAIL = spider WIN?
- Flesh-eating plant doubles as bat-cave
- Meat-eating plants with ultrafast traps
Go Further
Animals
- This ‘saber-toothed’ salmon wasn’t quite what we thoughtThis ‘saber-toothed’ salmon wasn’t quite what we thought
- Why this rhino-zebra friendship makes perfect senseWhy this rhino-zebra friendship makes perfect sense
- When did bioluminescence evolve? It’s older than we thought.When did bioluminescence evolve? It’s older than we thought.
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
Environment
- This pristine piece of the Amazon shows nature’s resilienceThis pristine piece of the Amazon shows nature’s resilience
- Listen to 30 years of climate change transformed into haunting musicListen to 30 years of climate change transformed into haunting music
- This ancient society tried to stop El Niño—with child sacrificeThis ancient society tried to stop El Niño—with child sacrifice
- U.S. plans to clean its drinking water. What does that mean?U.S. plans to clean its drinking water. What does that mean?
History & Culture
- Séances at the White House? Why these first ladies turned to the occultSéances at the White House? Why these first ladies turned to the occult
- Gambling is everywhere now. When is that a problem?Gambling is everywhere now. When is that a problem?
- Beauty is pain—at least it was in 17th-century SpainBeauty is pain—at least it was in 17th-century Spain
- The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’The real spies who inspired ‘The Ministry of Ungentlemanly Warfare’
- Heard of Zoroastrianism? The religion still has fervent followersHeard of Zoroastrianism? The religion still has fervent followers
Science
- Here's how astronomers found one of the rarest phenomenons in spaceHere's how astronomers found one of the rarest phenomenons in space
- Not an extrovert or introvert? There’s a word for that.Not an extrovert or introvert? There’s a word for that.
- NASA has a plan to clean up space junk—but is going green enough?NASA has a plan to clean up space junk—but is going green enough?
- Soy, skim … spider. Are any of these technically milk?Soy, skim … spider. Are any of these technically milk?
- Can aspirin help protect against colorectal cancers?Can aspirin help protect against colorectal cancers?
Travel
- What it's like to hike the Camino del Mayab in MexicoWhat it's like to hike the Camino del Mayab in Mexico
- Is this small English town Yorkshire's culinary capital?Is this small English town Yorkshire's culinary capital?
- This chef is taking Indian cuisine in a bold new directionThis chef is taking Indian cuisine in a bold new direction
- Follow in the footsteps of Robin Hood in Sherwood ForestFollow in the footsteps of Robin Hood in Sherwood Forest