“In my opinion, the main criterion when classifying a carnivorous plant is not that it eats insects, but primarily that it actively attracts prey,” says Fleischmann, who was not involved in the study. Suspicious of his sticky claws Western Triantha serve this purpose.

Nitrogen 15 is the proof

Proving that it is a carnivorous plant is more difficult than it seems. To do so in case Western Triantha Qianshi Lin and colleagues fed 150 fruit flies on nitrogen-15 medium. This is a stable nitrogen isotope that has an extra neutron that can be traced during the transfer of nutrients from animals to plants.

Scientists fed 25 samples of prepared flies Western Trianthathat grew in a swamp in British Columbia, Canada. They placed the insects on the stems of the plant, harvested the plants a few weeks later, and performed a chemical analysis. This showed that the leaves contained nitrogen-15, evidence that the plants had eaten the prepared flies and absorbed the nutrients in it. 64 percent of the nitrogen in the study plants came from these flies.