Plant growth is characterized by indeterminate growth, meaning that plants continue to grow throughout their lives without a predetermined endpoint. This growth is facilitated by meristems, which are collections of plant stem cells capable of producing daughter cells that can differentiate into various mature cell types necessary for the plant's development.

Primary growth, distinct from secondary growth, involves the elongation of roots and shoots. This process allows plants to extend their roots deeper into the soil and their shoots higher into the light. Depending on environmental conditions, plants may adapt their growth patterns; for instance, if there is little competition for light, they may spread their shoots horizontally to maximize sunlight absorption, akin to expanding a solar panel.

The apical meristem, located at the tips of roots and shoots, plays a crucial role in this growth. The shoot apical meristem is responsible for producing new leaves, flowers, and stems, while the root apical meristem generates new roots. These meristems are essential for the plant's ability to grow and adapt to its environment.

From the apical meristems, primary meristems differentiate into three main types that contribute to the plant's tissue systems: the protoderm, procambium, and ground meristem. The protoderm forms the epidermis, the outer protective layer of the plant. The procambium develops into vascular tissue, which is crucial for the transport of water, nutrients, and food throughout the plant. It also gives rise to lateral meristems, such as the vascular cambium and cork cambium, which contribute to secondary growth.

The ground meristem produces ground tissue, which encompasses all plant tissues that are neither vascular nor dermal. In roots, this tissue is found in the internal areas, while in shoots, it is divided into pith (inside the vascular bundles) and cortex (outside the vascular bundles). Understanding these meristematic tissues is fundamental to grasping how plants grow and develop structurally and functionally.

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