pith
The vascular cambium produces secondary xylem (wood) and secondary phloem, which are formed in a lateral direction. These structures are produced between the primary xylem and primary phloem in stems and roots of plants. The secondary xylem is produced toward the interior, while the secondary phloem is produced toward the exterior, contributing to the increase in girth of the plant.
primary xylem is primary in nature & is derived from procambium. But secondary xylem is secondary in nature and derived from fascicular cambium and interfascicular cambium. Primary xylem is differentiated into protoxylem and metaxylem, but secondary xylem has no such differentiation. In primary xylem vessels and tracheids are long and narrow, and vessels don't have tyloses, but in secondary xylem, vessels are blocked by tyloses, and vessels and tracheids are wider and shorter. Xylem fibres are more abundant in secondary xylem , and found in small numbers in primary xylem. Also unlike in primary xylem, secondary xylem has differentiated into sapwood & heartwood.
Secondary xylem
C. secondary xylemI'm positive its c. secondary xylem
secondary xylem
secondary xylem
secondary xylem
The precambium is a layer of meristematic tissue found between the primary xylem and phloem in vascular plants. It is responsible for the production of secondary vascular tissue in the form of secondary xylem (wood) and secondary phloem.
1. Normal type of secondary growth in the cortical and vascular regions adding to the secondary xylem ,secondary phloem and periderm at their proper places 2. Various types of anomalous secondary growth putting paches of xylem & phloem abnormally.
xylem and phloem
Secondary Xylem
secondary xylem and phloem.