SHOOTS
Secondary Tissues in Stems
Secondary phloem tissue
in stems is very similar to secondary phloem tissue in roots and
is composed of the same cell types.
Secondary Phoem Sieve Tube Elements,
Maceration
Secondary xylem tissue in stems is also very similar to that of roots. Two connected vessel elements are shown in the image at left. In addition to the end plates located between the two vessel elements, they also have lateral perforation plates. These plates allow water and minerals to move laterally through the tissue.
The granular material in the septate fibers is composed of amyloplasts-- starch storing plastids.
Secondary Xylem Vessel Elements and Septate
Fibers.
At left is an image of
pith parenchyma cells under polarized light.
Secondary Pith Parenchyma XS, Polarized
Light.
