Primary Meristems

Primary meristems are layers of meristematic tissue produced by the apical meristem of a vascular plant. Three kinds of primary meristem exist:

• Protoderm, which matures into the dermal tissue system;
• Procambium, which matures into the vascular tissue system;
• and Ground meristem, which matures into the ground tissue system.

The primary meristems can be found surrounding the apical meristem in the stem tip. Additionally, though most of this meristematic tissue permanently differentiates into new cell types, some exceptions exist. Residual procambium remains around many of the vascular bundles in the pith ray of the stem. In other older bundles, the residual procambium and parenchyma cells have differentiated into vascular cambium.