leaf scar
{{Short description|Mark left after a leaf falls off a twig}}
A leaf scar is the mark left by a leaf after it falls off the twig. 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|date=September 2024}}
Formation
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. Stipules may also leave their own scars if they are present.{{cite web|title=Winter twigs|url=http://osupress.oregonstate.edu/book/winter-twigs/intro|website=Oregon state university|accessdate=8 November 2015}}
Bundle scars
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.{{cite book|last1=Dirr|first1=Michael Illustrations by Bonnie Dirr|title=Manual of woody landscape plants.|date=1990|location=[S.l.|isbn=0-87563-344-7|edition=4. ed., rev.}} The number of bundle scars in a leaf scar is sometimes used as an identifying mark as they are often consistent across a species.{{citation needed |date=July 2023}}
File:20150304Aesculus hippocastanum1.jpg leaf scar showing seven bundle scars]]
