A breakthrough in plant science has validated Charles Darwin’s historic conjecture surrounding carnivorous Saxifraga species. Researchers discovered that these plants ensnare small gnats with sticky hairs, emitting fragrances that lure their prey. Chemical tests confirmed that insects provide essential nutrients upon capture, as showcased by isotope labeling. This pivotal finding sheds light on the complex interactions and nutritional strategies of plant carnivory in mountainous regions.
About 150 years ago, famous British naturalist Charles Darwin observed the sticky “hairs” on two plant species in the Saxifraga genus and wondered if some plants in the genus could be carnivorous. While he was unable to prove it then, more than a century later, scientists have shown that Darwin’s suspicions were correct.It was in 1875 that Darwin proposed that Saxifraga rotundifolia and S. umbrosa were insect eaters. The plants’ hairlike structures called glandular trichomes ooze a sticky goo and resemble hair found in other carnivorous plants. However, to be carnivorous, a plant must lure, trap and consume insects, and Darwin’s experiments with Saxifraga plants couldn’t conclusively demonstrate that the plants fit the bill.In a study published on Tuesday in the journal Nature Communications, researchers tested Darwin’s hypothesis by experimenting with Saxifraga candelabrum, a flowering mountain plant that grows at high altitudes on the southern part of the Qinghai-Tibet Plateau and in the Hengduan Mountains in China’s Yunnan and Sichuan provinces.
