Tree bark offers great opportunity to identify a tree during the winter. Some more straightforward than others. One tree that through its bark is a cinch to figure out, Common Hackberry (Celtis occidentalis). Its bark makes me think of a 3D topo map with all the ridges and valleys laid out and wrapped around the trunk.

The amount of furrowing increases as the tree ages. This image above is a younger tree than in the first photo.

Another point I pick up on in identifying, no matter what the season is, is the presence of Hackberry Galls, which are very often present on the twigs or leaves. These are caused by irritation of cells due to an insect called a Psyllid feeding on the Hackberry leaves and small branches.

In early summer you will find drupes (the fruit of the Common Hackberry Tree) on the trees. As the drupes mature they will go from green to a rich coppery purple color.

One last morsel of information not related to the identification of this tree is about a butterfly. The Hackberry Emperor (Asterocampa celtis) depends on the Common Hackberry Tree as its exclusive caterpillar host plant. No Common Hackberry Trees, no Hackberry Emperors.