Xylem (from the Greek "xylon" - wood) is one of the two main types of conducting tissue in plants, along with phloem. It plays an important role in the transport of water and mineral salts from the root of the plant to its leaves and other organs. Xylem can also serve as supporting tissue, providing a rigid structure for the plant.
Xylem consists of two main types of cells: tracheids and vessels. Tracheids are long, narrow cells with a diameter of about 0.02-0.05 mm that have a hole at the end. They are arranged vertically and connected to each other, forming long chains. Tracheids are typically found in more primitive types of plants, such as ferns and conifers.
Vessels are more developed structures consisting of shorter, wider cells that also have an opening at the end. They are located vertically and connect to each other, forming pipe-like strands