The trunk and older, thicker branches are woody, while the young branches become woody at the end of the growing season.
Its main purpose is to raise the leaves above the ground, allowing the tree to break through other plants and gain access to light. The trunk transports water and nutrients from the roots to the above-ground parts and distributes nutrients produced by the leaves to all other parts, including the roots. The outermost layer of the trunk is the bark, which is composed mainly of dead cells.
