Credit: From “Unique Growth Strategy in the Earth's Frist Trees Revealed in Silicified Fossil Trunks from China,” by Hong-He Xu, Christopher M. Berry, William E. Stein, Yi Wang, Peng Tang and ...

An update to da Vinci’s elegant, 500-year-old “rule of trees” offers a powerful, new way to describe the structure of almost any leafy tree.