A new study by Derek Moulton and colleagues at the University of Oxford has uncovered how the shape of rimmed leaves in carnivorous pitcher plants impacts their ability to trap insect prey. Carnivorous pitcher plants such as the genus Nepenthes have evolved leaves shaped like pitchers that fill with fluid and lure insects inside. The rim of the pitcher, known as the peristome, is critical to capturing insects through its specialized slippery surface.

While the peristome has been well-studied, researcher Derek Moulton and colleagues noticed the wide variation in peristome size and geometry across different pitcher plant species. How these differences affect the pitcher’s insect trapping capabilities has been unknown. The researchers wanted to test if peristome shape influences prey capture.

To investigate this, the team developed mathematical models representing different peristome shapes and tested insect sliding dynamics on the virtual surfaces. This novel approach combined geometry and physics to link peristome form to prey trapping function for the first time. The findings, published in PNAS, provide new evolutionary insights into the diversity of this specialized carnivorous plant group.