As a plant’s shoot apical meristem ages, the morphology and chemistry of the organs it produces change to match the selection pressures that are reliably associated with the different phases of growth. These developmental shifts in adaptive phenotypes are often most pronounced in woody perennials where the environment experienced by a small seedling is radically different than that of a mature tree. Two of the most common traits that shift over a tree’s life span are changes in the morphology of juvenile and adult leaves, and the duration of a juvenile reproductive phase (juvenility). In...
