Undifferentiated cells in plants found in merismatic regions in the root tips that are similar to stem cells in animals and can differentiate into any type of plant cell is called merismatic tissues.
Meristematic cells are analogous in function to stem cells in animals. Furthermore, the cells are small and protoplasm fills the cell completely. The vacuoles are extremely small. The cytoplasm does not contain differentiated plastids (chloroplasts or chromoplasts), although they are present in rudimentary form (proplastids). Meristematic cells are packed closely together without intercellular cavities.