Primary Growth
Tree growth occurs in two ways. Growth from the
root and shoot tips resulting in increases in height
and length is called primary growth. Growth that
increases the thickness of stems and branches is called
secondary growth. Primary growth occurs in small
areas called apical meristems. All leaves, height growth
and increases in the length of branches and roots are
the result of growth at the apical meristems. Here
one or more leaves are produced at a region called a
node, followed by a section of stem that is called the
internode.