Bundle trace (syn. bundle scar): Scar left on a twig by the vascular bundles when a leaf falls.*
Different plants have different numbers of bundle traces in their leaf scars. They appear as tiny dots within the borders of each leaf scar. These can be a very useful characteristic to use when identifying woody plants in winter. For instance, Ginkgos have 2 bundle traces per leaf scar.
*Harris, J.G., Harris, M.W. (2001). Plant identification terminology: An illustrated glossary (2nd ed.). Spring Lake: Spring Lake Publishing.