A seed scar, also known as a hilum, is a mark left on a seed's outer coat. This mark indicates the point where the seed was once attached to the plant's ovary wall or the funiculus (the stalk connecting the seed to the ovary). Think of it as a tiny "belly button" for the seed.
Understanding the Hilum
- Formation: The hilum forms after the seed matures and detaches from the parent plant. The connection point breaks, leaving behind a visible scar.
- Appearance: Hilums vary in appearance depending on the seed type. They can be oval, linear, or have other shapes. On a bean seed, the hilum is often referred to as the "eye."
- Importance: While seemingly insignificant, the hilum serves as a crucial landmark for botanists and seed scientists. It helps in identifying different species and understanding seed development. It can also sometimes be used to determine seed orientation for optimal planting.
Examples of Seed Scars
- Beans: The "eye" on a bean is a readily visible hilum.
- Other Seeds: Many other seeds have less noticeable hilums, requiring closer examination to identify.
The provided text mentions seed scarification, which is a different process altogether. Seed scarification is the deliberate weakening or breaking of a seed coat to aid germination, not the natural mark left after seed development.
