noun
- the first-formed xylem tissue in a plant, consisting of narrow vessels that develop during primary growth
Usage: botanical
Examples
- The protoxylem forms before the metaxylem during stem development.
- Botanists can identify protoxylem by its characteristically narrow vessel elements.
- In young roots, protoxylem appears at the center of the vascular cylinder.
- The protoxylem vessels are often stretched and destroyed as the plant grows.
- Students examined cross-sections to locate the protoxylem in plant stems.
- Primary xylem consists of both protoxylem and metaxylem tissues.