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Tissue in the vascular system of plants that moves water and dissolved nutrients from the roots to the leaves and also provides mechanical support. Xylem is of two kinds: primary, formed by differentiation from procambium and consisting of protoxylem and metaxylem, and secondary, additional xylem produced by activity of cambium. Xylem is characterized by the presence of tracheids and/or vessels, fibers, and parenchyma. In mature woody plants, xylem makes up the bulk of vascular tissue itself and of the entire structure of stems and roots.

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