xylem

[ zahy-luhm, -lem ]

noun

, Botany.

1. a compound tissue in vascular plants that helps provide support and that conducts water and nutrients upward from the roots, consisting of tracheids, vessels, parenchyma cells, and woody fibers.

xylem

/ ˈzaɪləm; -lɛm /

noun

1. See metaxylem, protoxylem
   a plant tissue that conducts water and mineral salts from the roots to all other parts, provides mechanical support, and forms the wood of trees and shrubs. It is of two types (protoxylem and metaxylem), both of which are made up mainly of vessels and tracheids See also protoxylem metaxylem

xylem

/ zī′ləm /

1. A tissue in vascular plants that carries water and dissolved minerals from the roots and provides support for softer tissues. Xylem consists of several different types of cells: fibers for support, parenchyma for storage, and tracheary elements for the transport of water. The tracheary elements are arranged as long tubes through which columns of water are raised. In a tree trunk, the innermost part of the wood is dead but structurally strong xylem, while the outer part consists of living xylem, and beyond it, layers of cambium and phloem.
2. See more at cambiumCompare phloem

xylem

1. The system of vessels that transports water in a plant. ( See phloem .)

Word History and Origins

Origin of xylem¹

1870–75; < German, equivalent to Greek xýl ( on ) wood + -ēma ( phloem )

Word History and Origins

Origin of xylem¹

C19: from Greek xulon wood

Example Sentences

This strategy suggests that the negative pressures of xylem sap can exceed one megapascal.

From Science News

Such a feat seemed so unlikely for the tiny insects that some scientists questioned whether xylem sap truly could be under such negative pressures.

From Science News

Extra xylem and phloem help the stem pump more food and water into the fruit, leaving less for the rest of the plant.

From Science News For Students

Xylem, zī′lem, n. the woody part of vegetable tissue—opposed to the phlom, or bast part.

From Project Gutenberg

All round the xylem and the phloëm there are many thick-walled cells.

From Project Gutenberg

These vessels together with the numerous small thick-walled cells lying between the pitted vessels constitute the xylem.

From Project Gutenberg

Just above the xylem there is a group of large and small thin-walled cells.

From Project Gutenberg

The larger bundles are normal in every way, while in the smaller ones the xylem elements are considerably reduced.

From Project Gutenberg