- Author: Cheryl Carmichael, Master Gardener
These terms are important factors for choosing the right tree for the intended space, planting and training the tree, and managing the overall tree size and shape.
Excurrent Tree Form: A tree form that develops when the central leader outgrows the lateral branches forming a narrow, cone-shaped form with a clearly defined central trunk. The regulation of the form is by an actively growing apical bud (meristem). This is common for most gymnosperms.
Decurrent Tree Form: A tree or shrub form that develops when there is weak apical dominance resulting in a rounded or spreading tree crown. This is common in most angiosperms.