Definition - What does Secondary Xylem mean?
Secondary xylem refers to the formation that occurs after the vascular cambium’s secondary growth. This type of xylem is not present in non-woody plants, but is commonly seen in shrubs and trees.
Secondary xylem consists of larger-sized vessels and tracheids. The cell walls of a secondary xylem are normally thickened by lignin deposition, which provides excellent mechanical support to the plant.
MaximumYield explains Secondary Xylem
Secondary xylems are found in two main gymnosperm groups. In angiosperms, for example, secondary xylems are not often found in monocots but rather in non-monocot trees, where the xylem is marketed and used as hardwood. In conifer species, secondary xylems feature a uniform structure and are used as softwood.
Secondary xylems can be used to distribute soluble mineral nutrients as well as water throughout the plant. In some cases, it also replaces the water lost during the process of photosynthesis and transpiration.
Unlike primary xylem, secondary xylem occurs in patches from the center of the plant.