What is the difference between phellem and phelloderm?
Some plants tend to experience secondary growth in the roots and stems. These parts of the plant have peripheral tissues that exhibit secondary growth.
The first phase of secondary growth in stems and roots is mainly focused on the epidermis, hypodermis, and cortex. The second phase is exhibited on periderm.
The periderm is divided into phellem, phelloderm, and phellogen. The phellogen tissue is responsible for producing phellem and phelloderm.
The core difference between phellem and phelloderm is that phellem is the actual cork while phelloderm is the secondary cortex.
What Is a Phellem?
Phellem is produced by the phellogen tissue and it occurs towards the outside. The cells are closely packed and they are mainly dead cells.
The lenticels are mainly found on the phellem and it is covered by the tannin. Besides that, the tissue tends to be impermeable to water.
What Is a Phelloderm?
Phelloderm is produced by the phellogen and it occurs towards the inner side. The cells are loosely packed and they are mostly living cells.
The tissues are responsible for the storage of food materials and they are also permeable to water. The secondary cortex tends to lack tannin deposition.
Comparison Chart: Phellem vs Phelloderm
| Basic Terms | Phellem | Phelloderm |
| Meaning | It is a cortex tissue produced by phellogen towards the outside | It is a cortex tissue produced by the phellogen towards the inside |
| Type of cells | Dead cells | Living cells |
| Significance | To provide protection | To offer storage for food materials and ergastic substance |
| Arrangement of cells | Closely packed | Loosely packed |
| Location | Outside | Inner side |
| Alternative name | Cork | Secondary cork |
| Water permeability | Impermeable | Permeable |
| Suberized | Highly suberized cells | Cells not suberized |
| Tannin deposition | Present | Absent |
| Pores or lenticel | Present | Absent |
Core Differences between Phelloderm and Phellem In Point Form
- Phellem is a tissue produced by phellogen towards the outside while phelloderm is produced towards the inner side
- Phellem is also known as cork while phelloderm as the secondary cortex
- Phelloderm have living cells while phellem have dead cells
- The cells of phelloderm are loosely packed while those of phellem are closely packed
- Phellem provide maximum protection while phelloderm offer storage space for food materials and other substance
- The cells of phellem are highly suberized while phelloderm cells are not suberized
- The cells of phellem have tannin deposition while that of phelloderm tend to lack tannin deposition
- The phellem have pores while phelloderm lack pores
- The phellem are impermeable to water while phelloderm are permeable to water
- The phellem occur on the outside while phelloderm occur on the inner side
Similarities between Phellem and Phelloderm
- Both have secondary tissue
- Both are produced by the cork cambium
- Both form component of the bark
- Both are parenchyma cells
You May Also Like:
Comparison Video
Summary
The main difference between phelloderm and phellem is that phelloderm cells are loosely packed and permeable to water while phellem cells are closely packed and impermeable to water.