A Common North American Plant Was Just Discovered to Be Secretly Carnivorous

A plant-like herb that is found in the wetlands of North America's west coast - Alaska to California – has recently been discovered to occasionally taste for flesh.Triantha occidentalis uses insects to pollinate its normal-looking flowers. However, the plant also has sticky hairs below these flowers that trap small insects for snacking. This seems a little conflict of interest.The Venus flytrap (Dionaea mucipula), is the most common carnivorous plant that we can imagine eating insects, spiders or small animals. They are not the only carnivorous plant; there are more than 500, and we continue to discover more.T. occidentalis, the 12th evolution of carnivory known to have occurred in plants. It is also the first time that we have seen carnivory within the Alismatales order. There's a reason why more plants don't know how to digest animals.Tom Givnish, University of WisconsinMadison botanist, says that only in limited habitats would you expect carnivory as an advantage. A little bit of insect food can give you a boost when the soil is deficient in nutrients, especially nitrogen and phosphorus.The team fed the insects nitrogen-15-labeled fruit flies and was able to track how much nitrogen entered the plant as T. occidentalis ate its meal. Although this species was less nitrogen than other plants, it still had a significantly higher N-15 value than non-carnivorous counterparts. According to the team, 64 percent of this species' nitrogen came from insects.Hairs of T. occidentalis, some with trapped insects (arrows). (Lin et al., PNAS, 2021)T. occidentalis, however, isn't a standard carnivorous species. Although most carnivorous plants have flowers, they are usually placed far away from any other eating apparatus.For example, the Venus flytrap will produce a long stalk and a flower on its top to repel pollinators.Qianshi Lin (botanist at the University of British Columbia), leads the study. "What's most unique about this carnivorous plants is that it traps bugs near its insect-pollinated blooms," Lin says."On the surface this looks like a conflict between pollination and carnivory because you don’t want to kill insects that help you reproduce."It can be risky for your bees, butterflies or other pollinators to get stuck while you want them flying away to the next plant to spread your pollen.It seems, however, that the plant has an ingenious solution.Givnish says that T. occidentalis can do this because its hairs aren't very sticky and can only trap midges and other small insects so that larger, more powerful bees and butterflies who act as its pollinators don't get captured."Researchers are excited to discover that we have missed carnivory in the tiny plant, which is located close to cities.The study concludes that Triantha is found within close proximity of major Pacific coastal cities. This serves as a reminder that there may be other cryptic carnivores.The Proceedings of the National Academy of Sciences published the research.