Xylem, the basics | Tree Biology

First of two videos explaining what is xylem. It's one of two transporting tissues in plants, the other being phloem. This video covers the two main types of xylem transport cells (tracheids and vessel elements), and how the vessels are what distinguish a true "hardwood" (versus softwoods, which are not "soft wooded" trees, but rather trees that only have tracheids). Active xylem is sapwood - heartwood is inactive xylem that also has more decay resistive substances (but not decay immune)