Apical growth of Populus spp. I. Sequential pattern of internode, bud, and branch length of young individuals

Young individuals of Populus tremuloides Michx., P. grandidentata Michx., and P. balsamifera L. were studied at one locality in southern Ontario. The sequential patterns of apical growth as indicated by their internode, bud, and branch length are consistent and characteristic within but differ between each of the three species. The length of bud was closely correlated with the length of branch that subsequently developed from it. Angles of divergence and pattern of the primary branch length were also characteristic of each species and resulted in different crown forms. The study indicates that these sequential patterns are genetically controlled