The ground tissue system makes up the bulk of the plant body. The vascular tissue system contains two kinds of conducting tissues that distribute water and solutes through the plant body. The dermal tissue system covers and protects the plant's surfaces. Meristems Meristems are localized regions of self-perpetuating, embryonic cells. Descendants of some of these cells will develop into the specialized tissues of the elongating root and stem.
Growth originating at root and shoot tips is labeled primary growth.
Lateral meristem tissues are responsible for the increase in diameter of older roots and stems. Vascular cambium and cork cambium are the two kinds of lateral meristems. These are responsible for secondary growth, which adds to woody parts of trees, for example. Simple Tissues Parenchyma is the most abundant type. Its thin-walled, pliable cells are found in virtually all plant parts.