Buckthorn is usually the first shrub to leaf out in the spring and the last to drop its leaves late in the fall.
It often grows 2 to 3 meters tall. Occasionally it reaches 6 meters, with a trunk up to 25 centimeters in diameter.
It is distinguished by the sharp, thorn-tipped branches in contrast to the simple or compound thorns growing from the sides of branches in the Hawthorns.
It has smooth, dark green leaves that are finely toothed, 2.5 to 6 centimeters long, with prominent forward-curved side veins, arranged in opposing pairs along the stem.
It produces clusters of purplish-black berries along the stems and short twigs, and each berry usually has 4 hard seeds.
