Arrangement of leaves on a stem is called as Phyllotaxy. There are several methods that plants use to arrange leaves on their stem. It is basically 4 ways as,
In this arrangement, leaves are arranged alternatively on the stem with one leaf per node in a straight line.
Here, two leaves arise from a single node in opposite fashion.
Only one leaf is present per node as in alternate arrangement. But, the leaves are arranged as a spiral which would be visible if you look down at the apex of the stem.
Multiple leaves arise from a single node and each nodes are separated by huge internodes.
Other arrangements include Subopposite and Deccusate.
Here, the leaves are arranged in such a fashion that they are neither spaced far enough to be considered as alternate nor exactly opposite enough to consider as opposite.
This is where two leaves arise from a same node (opposite) in each nodes. The pairs are placed in right angles to each other.