leaf scar

A leaf scar is the mark left on a plant's stem after a leaf has fallen. This occurs as part of the natural process of senescence, where leaves age and detach from the plant.12

In plant anatomy, leaves are crucial for photosynthesis, the process by which plants create their own food using sunlight, water, and carbon dioxide. When a leaf reaches the end of its life cycle, or if it's damaged, an abscission layer forms at the base of the petiole (the stalk that attaches the leaf to the stem). This layer weakens, causing the leaf to fall. A healing layer then forms on the stem, closing the wound and leaving behind the distinct leaf scar. These scars can be helpful in identifying plants, especially on bare winter twigs.2