Meristeemisten

Meristeemisten refers to tissues in plants that are composed of actively dividing cells. These cells, known as meristematic cells, are undifferentiated or incompletely differentiated and retain the ability to divide throughout the plant's life, contributing to its growth. Meristematic tissues are crucial for plant development, enabling the elongation of roots and shoots and the formation of new organs.

There are two primary types of meristematic tissues: apical meristems and lateral meristems. Apical meristems are found at the tips of roots and shoots and are responsible for primary growth, which increases the length of the plant. Lateral meristems, such as the vascular cambium and cork cambium, are located in cylinders along the length of stems and roots and are responsible for secondary growth, which increases the girth or diameter of the plant. Intercalary meristems, a subtype, are found at the base of nodes or leaf blades and allow for rapid elongation in grasses and other plants, often after being cut or grazed.

The cells within meristematic tissues are typically small, isodiametric, and possess large nuclei and dense cytoplasm. They have thin cell walls and lack large vacuoles. Their continuous division leads to the formation of new cells that differentiate into various permanent tissues, such as parenchyma, xylem, and phloem, which perform specialized functions within the plant. The activity of meristeemisten is regulated by hormonal signals and environmental factors, allowing plants to adapt to their surroundings.