| 释义 |
WordReference Random House Unabridged Dictionary of American English © 2024xy•lem (zī′ləm, -lem),USA pronunciation n. [Bot.]- Botanya 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.
- German, equivalent. to Greek xýl(on) wood + -ēma (see phloem)
- 1870–75
Collins Concise English Dictionary © HarperCollins Publishers:: xylem /ˈzaɪləm -lɛm/ n - 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
Etymology: 19th Century: from Greek xulon wood |