1. It takes place by the activities of primary meristematic tissues such as apical cell, apical meristems, etc.
2. It results in growth in longitudinal axis mainly.
3. It is the first growth of the plant and its parts.
4. It is for a short period and stops after complete tissue differentiation occurs in a part of the plant.
5. It occurs in all plants and in all parts.
6. Periderm and barks are not formed.
7. Tissue formed by this growth are various types and called primary tissues.
1. It takes place by the activities of secondary meristematic tissues and some times by the joint activity of both primary and secondary meristematic tissues.
2. It results in radial growth.
3. It is a later period of growth.
4. It continues only in matured part and occurs after the part of organ has completely developed.
5. It occurs in gymnosperms and angiosperms (except monocots).
6. It results in the formation of bark periderm, lenticel, etc.
7. Tissues formed due to this growth are mainly secondary xylem and secondary phloem and are called secondary tissues.