From cloud gazing to seeing faces in toast, humans tend to find patterns where none exist, a tendency called apophenia. But sometimes the patterns are real. Scientists at Cold Spring Harbor Laboratory have now discovered a genuine geometric blueprint inside the leaves of the common houseplant Pilea peperomioides, also known as the Chinese money plant.
Led by Associate Professor Saket Navlakha and former graduate student Cici Zheng, now a postdoctoral fellow at the Allen Institute, the team mapped the position of microscopic pores called hydathodes. Around each pore, they found a looping vein network that precisely matches a Voronoi diagram: a mathematical system typically used in computer science and urban planning. This is the first confirmed example of a Voronoi pattern with visible centre points in nature.
Curiously, plants cannot measure distance. "They rely on local biological interactions to achieve the same Voronoi solution," Zheng explains in the university's news release. The team, working with computer scientist Przemysław Prusinkiewicz, identified a natural mechanism involving the plant hormone auxin. The discovery, published in Nature Communications, resolves a decades-old mystery about how loops form in leaf veins. "This example is a nice merger of classical geometry, modern plant biology and computer science," Navlakha said.