Description:
Typical of roots is that the vascular tissue is organised as a central and solid cylinder. In dicots, the xylem forms a 3-, 4- or 5-pronged solid star with the metaxylem in the middle and the protoxylem poles touching the pericycle. Phloem and parenchyma are located between the xylem strands. In this section, a part of the metaxylem is not differentiated as some vessel elements are lacking a secondary cell wall. The vascular cylinder is surrounded by an endodermis with uniformly thickened cell walls. In some cases the endodermis cells facing the protoxylem poles lack thickened cell walls and are called ‘passage cells’.

Images:


Slide information:
- Section/photo: Olivier Leroux
- Paraffin section
- 8 micrometer
- Chrysoidin-astrablue staining