Staminate inflorescences are axillary clusters of two to eight flowers on current year's spurs. Lobes are 2-3 mm long. The corolla consists of four petals. Pistillate inflorescences are in axillary clusters of two to 15 flowers on current year's spurs. The pistillate calyx is similar to the staminate calyx.
Petals are usually absent.
Each drupe contains four seeds. The inner surface is prominently ridged, and the outer surface is grooved. Lenticels occur as narrow vertical slits. The bark of the trunk is slightly scaly and light to dark gray in color with horizontal lenticels. Common buckthorn is a native to Europe and is now naturalized in most of northeastern North America.