A mature vascular plant (any plant other than mosses and liverworts), contains several types of differentiated cells. These are grouped together in tissues. Some tissues contain only one type of cell. Some consist of several. Meristematic
The main function of meristematic tissue is mitosis. The cells are small, thin-walled, with no central vacuole and no specialized features. Meristematic tissue is located in
•the apical meristems at the growing points of roots and stems. •the secondary meristems (lateral buds) at the nodes of stems (where branching occurs) [View], and in some plants, •meristematic tissue, called the cambium, that is found within mature stems and roots. The cells produced in the meristems soon become differentiated into one or another of several types.
Protective tissue covers the surface of leaves and the living cells of roots and stems. Its cells are flattened with their top and bottom surfaces parallel. The upper and lower epidermis of the leaf are examples of protective tissue [View]. Parenchyma
The cells of parenchyma are large, thin-walled, and usually have a large central vacuole. They are often partially separated from each other and are usually stuffed with plastids. In areas not exposed to light, colorless plastids predominate and food storage is the main function. The cells of the white potato are parenchyma cells. [View] Where light is present, e.g., in leaves, chloroplasts predominate and photosynthesis is the main function. [View] Sclerenchyma
The walls of these cells are very thick and built up in a uniform layer around the entire margin of the cell. Often, the cell dies after its cell wall is fully formed. Sclerenchyma cells are usually found associated with other cells types and give them mechanical support. Sclerenchyma is found in stems and also in leaf veins. [View] Sclerenchyma also makes up the hard outer covering of seeds and nuts. Collenchyma
Collenchyma cells have thick walls that are...