Meristems are a group of cells that actively divide to form new cells and have various functions according to their location:
A. Apical Meristem
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This tissue present at the apex of shoot, their branches and roots helps in increase in the length (primary growth).
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The protoderm formed by the apical meristem gives rise to epidermis and epiblema of the stem and root, respectively.
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The procambium forms the vascular tissues (Primary phloem and xylem and the interfascicular cambium).
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The ground meristem gives rise to pith, pericycle, endodermis, cortex and hypodermis (Ground tissues).
B. Intercalary Meristem
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These also help in primary growth by elongation of organs.
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Regeneration of damaged/injured parts between the mature tissues e.g., at the base of leaves and at nodes is also a function of the intercalary meristem.
C. Lateral Meristem
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This tissue produces secondary growth i.e., increase in thickness or girth of the plant. For example, vascular cambium in the root and interfascicular cambium in stem.
