B) Meristems based on position:
On the basis of position, meristems may be classified into the following three types:
1. Apical meristem
2. Intercalary meristem
3. Lateral meristem.
1) Apical meristem:
These meristems are found at the apices of stem and root.
They are responsible for increase in linear growth (length) of the plant body.
2) Intercalary meristem:
These meristems are present between masses of permanent tissues.
These are the portions of apical meristems which are separated from the apex during the growth of axis and formation of permanent tissues.
They may be present either at the base of internodes, (as in grasses and wheat) or at the base of node, (as in mint).
The activity of these meristems also adds to the length of the plant or its organs.
They originate from apical meristems and are short lived.
3) Lateral meristem:
These meristems are arranged parallel to the longitudinal axis of plant in stem and branches.
It is composed of initials which divide mainly in one plane (periclinally) and increase the diameter or girth of stem and branches.
Cork cambium and vascular cambium are the examples of lateral meristem.
