Leaf scar

It marks the site where the petiole attached to the stem.

A leaf scar is typically found below a branch, as branches come from axillary buds located above leaf scars.

[citation needed] Leaf scars are formed naturally, often at the end of the growing season for deciduous plants when a layer of cells called the abscissa layer forms between the petiole and stem.

The abscission layer acts as a point of cleavage and the leaf breaks off leaving a cleanly shaped wound that is quickly healed over with protective cork.

[1] Bundle scars are circular or barred regions within the leaf scar where bundles of vascular tissue that had connected the leaf and the stem broke off.