1. a protective sheath that covers the emerging shoot of a grass seedling
Usage: botanical

Examples

• The coleoptile protects the delicate shoot as it pushes through the soil.
• Scientists studied how light affects coleoptile growth in corn seedlings.
• The coleoptile eventually splits open to allow the first leaves to emerge.
• Researchers measured the length of the coleoptile in different experimental conditions.
• The hormone auxin plays a key role in coleoptile elongation.
• Students observed the coleoptile under a microscope during their botany lab.