[proh-tuh-zahy-luh m, -lem]
- the part of the primary xylem that develops first, consisting of narrow, thin-walled cells.
Origin of protoxylem
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the first-formed xylem tissue, consisting of extensible thin-walled cells thickened with rings or spirals of ligninCompare metaxylem
- The first formed xylem that differentiates from the procambium.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.