KEY POINTS

  • The Triantha occidentalis is a perennial herb
  • It traps prey in the sticky hair on its stalk, where it produces a digestive enzyme
  • It is quite common and grows near "several major urban centers"

Researchers have discovered that a plant known to science for many years is actually carnivorous. This breakthrough suggests there may be other interesting ecological finds that have yet to be uncovered.

The Triantha occidentalis is a perennial herb that can be found along the West Coast of North America, the researchers of a new study, to be published Aug. 13 on PNAS, said. Also known as the western false asphodel, the monocot was first described in the scientific literature in 1879.

However, it turns out that the plant, which grows lovely-looking white flowers in nutrient-poor habitats such as wetlands and bogs, isn't as innocent-looking as it seems. In fact, it is carnivorous.

Cute but Deadly

Researchers were working on another project when they noticed the western false asphodel was actually lacking a gene that other carnivorous plants were also missing, reported NPR. What's more, the plants also had rather sticky stems onto which insects could get trapped.

To find out if the plant was indeed carnivorous, the researchers fed the flowers with fruit flies labeled with isotope nitrogen-15 so they could track the nutrient once it entered the plant, the University of Wisconsin-Madison noted in a news release.

Sure enough, the researchers found that it actually acquired up to 64% of its nitrogen needs from insects. This is comparable to the nitrogen uptake in other carnivorous plants and far above the incidental uptake in non-carnivorous plants.

The researchers also found that the sticky hair on the plants' stalk produced phosphatase, which is the digestive enzyme that many carnivorous plants use to break down phosphorous in prey.

"We conclude that T. occidentalis should be welcomed to the small but fascinating ecological guild of carnivorous plants," the researchers wrote.

This makes it the first new carnivorous plant botanists have identified in 20 years, the University of British Columbia (UBC) noted in a news release.

"This is the 12th known independent evolution of carnivory in the plant kingdom, and the first time the trait has been discovered in the Alismatales order, a group of largely aquatic flowering plants," the University of Wisconsin-Madison news release noted. "It is also just the fourth established instance of carnivory in the monocots, one of the major groups of flowering plants."

A Flower That Can Determine Friend From Prey

A particularly interesting find is that Triantha traps its prey "near its insect-pollinated flowers," study lead Dr. Qianshi Lin, who was previously a Ph.D. student at UBC Botany, noted. According to the researchers, "almost all" carnivorous plants position their flowers and their traps far away from each other to "minimize the conflict between pollination and prey capture." 

So how does the T. occidentalis determine friend from prey?

"We believe that Triantha is able to balance carnivory with pollination because its glandular hairs are not very sticky and can only trap midges and other small insects, so that the much larger and stronger bees and butterflies that act as its pollinators are not captured," study co-author, Tom Givnish of the University of Wisconsin-Madison, said as per the UBC news release.

According to the researchers, the find shows just how much more there is left to discover.

"(T)he fact that T. occidentalis was hidden in plain sight as a carnivorous plant, despite its proximity to several major urban centers on the Pacific coast of North America, is remarkable," the researchers wrote. "This serves as a reminder that other cryptic carnivores may yet remain to be uncovered and that much is still to be learned about the ecology of individual plant species, even in relatively well-known floras."

Peat Bog/Moor/marsh Representation of a peat bog/moor. Photo: Pixabay