noun
- A tubular or sheath-like structure formed by the fusion of stipules around a stem in certain plants.
Usage: botany; also spelled 'ochrea'
Examples
- The ocrea of the knotweed plant encircles the stem at each node.
- Botanists identified the plant by examining the distinctive ocrea structure.
- In plants of the Polygonaceae family, the ocrea serves as a protective sheath.
- The ocrea is formed when two stipules fuse together around the stem.