Different species of tree have distinct characteristics, and we usually recognize trees by their leaves or flowers. However, in early spring term, many trees on campus still have no leaves or flowers. How should we recognize different tree species on campus then? Tree bark!
One of the tree species on campus that has distinct tree bark is paper birch. The bark of all birches is characteristically marked with long, horizontal marks called lenticels, and often separates into thin, papery plates. As for the paper birch, one of the most distinct characteristics is that it has white bark. Since not many trees on campus have white-colored bark, it is very likely that you have encountered a paper birch when you see a tree with white bark. The bark of birch is very useful. Since the cardboard-like bark is strong and water-resistant, it can be easily cut, bent, and sewn, which has made it a valuable building, crafting, and writing material since prehistoric times. Even today, birch bark remains a popular type of wood for various handicrafts and arts.
In addition to paper birch, Kentucky coffeetree is another tree species on campus that can be easily identified based on its bark. The Kentucky coffeetree is a tree in the pea family, native to the central part of eastern North America. The seed may be roasted and used as a substitute for coffee beans. Different from that of the paper birch, the bark of Kentucky coffeetree is tan or dark gray, deeply fissured, often with prominent narrow ridges and a scaly surface.
Now we have learned how to use tree bark to identify birch tree and Kentucky coffeetree. So it’s time to go out and see how many birch trees and Kentucky coffeetrees you can find on campus or in the Arb!
–Starr Wang ’21, for the Cole Student Naturalists
If you want more information on the Kentucky coffeetree, read this Arb Note by Callen Inman ’19