According to cell division, dividing tissue is divided into three parts.
(i) Rib meristem: The dividing tissue which divides at one level is called Rib meristem. It is called rib dividing tissue because it looks like the rib of the chest. For example, spinal cord.
(ii) Plate meristem: The dividing tissue which divides into two layers is called plate meristem. Cells are single-layered and plate-like, so called squamous tissue. Division of plate dividing tissue results in flattened, elongated plant organs that increase in length and width. It increases the volume and area of plant organs. For example, the bark, leaves, etc.
(iii) Mass meristem: The dividing tissue which divides at all levels is called mass dividing tissue. It is randomly arranged to form cell islands. It increases the volume or density of plant organs. For example, embryo, follicle, endosperm, cortex, marrow etc.