Leafscars

leafscar, bundle scars and bud of Pecan twig

When leaves fall off before winter they leave leafscars on the twigs. The image at the right shows a much-magnified part of a Pecan tree twig from near my trailer. Note the dark bundle scars inside the leafscars. These scars result from the breaking of the pipe-like vascular bundles passing from the twig into the leaf's petiole. Vascular bundles consist of the plant's xylem and phloem, described on our Inside Twigs Page.

Now just look at the variety of leafscars and buds in the picture below:

leafscars of black oak, fig, red buckeye, bitternut hickory, pawpaw, boxelder, sycamore & chinaberry

As you can see, leafscars and buds vary tremendously from species to species. Therefore, during winter they are great help to backyard naturalists trying to identify tree species using twig characteristics. In the above image, notice these things:

the Black Oak's bud bears many overlapping scales but the Sycamore just has one big scale
the Fig's leafscar is oval, the Boxelder's V-shaped, and the Sycamore's almost circular
vascular bundles are arranged differently from leafscar to leafscar
- neatly collected into five little dots in the Pawpaw
- but in three broad C-shaped regions in the Chinaberry
some twigs like the Fig's and the Chinaberry's are thick, while others like the Boxelder's are slender
twigs come in different colors -- especially the green Boxelder

You see? You really can identify woody species even after their leaves have fallen!