Secondary growth: Growth of plants in girth (diameter) which occurs due to the formation of secondary tissue from vascular cambium and cork cambium is said to be secondary growth.
Secondary growth gives rise to two types of secondary tissues:
- Vascular secondary tissue.
- Periderm tissue.
Vascular secondary tissue: Vascular secondary tissues are formed due to the division of vascular cambium, such as- secondary xylem and secondary phloem
Periderm: Penderm is formed due to the division of cork cambium Phelogen, phelobderm, cork etc are combinedly known as periderm.
Types of secondary growth:
Due to the variation of tissue, secondary growth is of two types
- Normal secondary growth
- Abnormal secondary growth
It can be differentiated into two types on the basis of regions
- Interstellar secondary growth
- Extrastellar secondary growth.