Meristem

An embryonic tissue of a plant, analogous in function to stem cells in animals. Meristematic cells are differentiated incompletely or not at all. Differentiated plant cells often have unique structures that would make it problematic for them to produce cells of a different type; thus, the plant draws upon meristematic tissue to grow.

The most general form of meristem is the apical meristem, found in buds at the tips of shoots and roots. Apical meristem is completely undifferentiated. It differentiates into three different kinds of primary meristem:

• Protoderm[?] lies around the outside of the stem, and develops into the epidermis[?].
• Procambium[?] lies just inside the protoderm. It develops into the primary xylem, primary phloem. It also produces the vascular cambium, which may continue to produce secondary xylem and phloem throughout the life of the plant.
• Ground meristem[?] develops into the pith[?] and the cork cambium.

The vascular cambium and cork cambium are called lateral meristem, because they lie around the sides of established stems.

The comprehensive textbook Biology, 6th ed., by Neil A. Campbell and Jane B. Reece, published by Benjamin Cummings, has been used as a source.