what does protophloem differ to metaphloem?
Protophloem | Metaphloem |
It is the first formed phloem when the plant organ is growing. | It is the later formed phloem which differentiates when the plant organ has completed its growth. |
It is less prominent. | It is more prominent. |
It is made up of smaller and narrower elements. | It is made up of longer and broader elements. |
Sieve areas or pores are not prominent. | Sieve areas or pores are quite prominent. |
Companion cells are often absent. | Companion cells are usually present. |
Protophloem is short lived and gets crushed. | It is long lived and can be crushed during secondary growth. |
In the region of crushed protophloem, fibers often develop from specialized cells. | Fibers may be present but specialized cells do not occur. |