Newly Discovered Carnivorous Flowers

Gleaming, gluey, deathtrap hairs have betrayed the secret identity of a well-known wildflower: It’s a carnivore. A species of false asphodel (Triantha occidentalis) uses enzyme-secreting hairs on its flowering stem to snare and digest insects. Scientists have known about T. occidentalis since the 19th century, but its taste for meat has gone undetected until now. Sticky hairs by themselves aren’t unusual — many noncarnivorous plants use them to defend against pests. But T. occidentalis has qualities that some meat-eating plants share: a love of bright, boggy, nutrient-poor habitats and the absence of a gene that fine-tunes how plants get energy from light.

To solve the puzzle, scientists needed to know if the wildflower pulls nutrients from insect corpses. Luckily, T. occidentalis grows along North America’s West Coast, from Alaska to California, and can be found on hikes near Vancouver.

Experiments confirm that Triantha occidentalis wildflowers are carnivorous, getting nutrients from insects that get caught in their sticky stem hairs (shown).QIANSHI LINThe team attached fruit flies fed with nitrogen-15, an isotope that can be used to track changes in nitrogen levels, to the flowering stems of bog-dwelling T. occidentalis plants in British Columbia’s Cypress Provincial Park. Over half of the wildflowers’ nitrogen came from the fruit flies, the team found. Those levels are comparable to known carnivorous plants. What’s more, the wildflowers’ sticky hairs oozed phosphatase, a digestive enzyme that many carnivorous plants secrete to consume prey.

CITATIONS Q. Lin et al. A new carnivorous plant lineage (Triantha) with a unique sticky-inflorescence trap. Proceedings of the National Academy of Sciences. Vol. 118, August 17, 2021. doi: 10.1073/pnas.2022724118.