noun
- The first-formed phloem tissue in plants, consisting of sieve tubes and companion cells that develop from the procambium during primary growth.
Usage: botanical term; plural of protophloem; technical/scientific usage
Examples
- The protophloems in young plant stems are responsible for transporting sugars during early development.
- Botanists distinguish between protophloems and metaphloems based on their developmental timing.
- The protophloems typically consist of narrow sieve tubes adapted for nutrient transport.
- In dicots, protophloems develop before metaphloems in the vascular bundles.
- The structure of protophloems reflects their role in the plant's initial growth phase.