|
|||
 |
Half of the Procambium usually produces Phloem. Phloem is generally opposite the Xylem and nearer to the Epidermis. The inner Procambial cells produce Xylem. | ||
 |
The first step in xylem differentiation is cell enlargement. This establishes the pattern in which Tracheary Elements will differentiate. The innermost xylem cells have the narrowest diameter. Those at the opposite pole have the largest diameter. | ||
 |
The next step is the deposition of thick,
lignified secondary cell wall in the walls of Tracheary Elements. The first cells to
develop these secondsry walls are those with the samllest diameters near the center of the
stem. These cells are called Protoxylem. Proto = First |
||
 |
This continues centrifugally (away from the center). This is called Endarch En = Inside. | ||
 |
Eventually, all of the Procambium cells destined to become Xylem differentiates! | ||
 Lecture Directory |
 Prior Page |
 Next Page |
 Home Page |
|---|---|---|---|
