Plant Anatomy: Tracheid vs Vessel

Xylem Tissue

• A tracheid is a non-living, elongated cell with tapering ends, with highly thickened walls made of lignin, except at circular spots known as pits.
• Vessels are cylindrical, tube-like structures placed end-to-end, with lignified walls, and partially or completely dissolved end walls to form a continuous channel.
• Both tracheids and vessels are non-living cells that provide mechanical support to plants and are the main conducting elements in the xylem.
• Xylem parenchyma consists of thick-walled, living cells that perform the function of storage.
• Xylem fibres are non-living, thick-walled cells that provide mechanical support to plants.

Occurrence of Xylem and Phloem

• Xylem and phloem usually occur together in the roots, stems, and leaves of higher plants, forming vascular bundles.

Functions of Xylem

• The main function of xylem is to conduct water and minerals from the roots to different parts of the plant body.
• Tracheids and xylem fibres provide mechanical support to plants.
• Xylem parenchyma helps in the storage of starch and other materials.

Phloem Tissue

• Phloem is a complex tissue consisting of both parenchymatous and sclerenchymatous cells.
• Phloem tissue consists of both living and non-living cells.
• Components of phloem tissue include sieve-tube cells, companion cells, and phloem parenchyma cells.
• Sieve plates are present in phloem tissue.