What Are Plant Tissues

Plant consists of three major organ groups: roots, stems, and leaves. As we know from other areas of biology, these organs are made up of tissues working together for a common purpose (function). In turn, tissues are made up of many cells that are made up of elements and atoms at a basic level. In this section, we will look at the different types of plant tissue and their location and purpose within the plant. It is important to understand that there may be slight variations and changes in the basic tissue types in particular plants.Plant tissues are characterized and classified according to their structure and function. The organs that they form will be organized into patterns within a plant which will aid in further classifying the plant. A good example of this is the three basic tissue patterns found in roots and stems which serve to delineate between woody dicot, herbaceous dicot and monocot plants. We will look at these classifications later

Meristematic Tissues

Tissues where cells are constantly dividing are called meristems or meristematic tissues. These regions produce new cells. These new cells are generally small, six-sided boxlike structures with a number of tiny vacuoles and a large nucleus, by comparison. Sometimes there are no vacuoles at all. As the cells mature the vacuoles will grow to many different shapes and sizes, depending on the needs of the cell. It is possible that the vacuole may fill 95% or more of the cell’s total volume. There are three types of meristems: (1) apical meristems, (2) lateral meristems, and (3) intercalary meristems.

Apical meristems

Apical meristems are located at or near the tips of roots and shoots. As new cells form in the meristems, the roots and shoots will increase in length. This vertical growth is also known as primary growth. A good example would be the growth of a tree in height. Each apical meristem will produce embryo leaves and buds as well as three types of primary meristems: protoderm, ground meristems, and procambium. These primary meristems will produce the cells that will form the primary tissues.