Common buckthorn

Encyclopedia Article

Common buckthorn                       Rhamnus cathartica L.

Family:  Rhamnaceae (Buckthorn family)

Life cycle:  Perennial

Habitat:   Edges of woodlands

General description:  Small tree reaching heights of 20 ft and trunk diameters of 10 in.  Leaves are broadly oval, pointed tip, with 3-4 pairs of curved vein; small teeth on margins.  Leaf arrangement is termed subopposite since they are not evenly spaced along stems. Twigs commonly tipped with sharp spine, trees vary widely in abundance of these spines.   The plant is dioecious, flowers produced in dense clusters of 2-6 in leaf axils; female plants produce clusters of black berries, approximately ¼ in diameter.  Inner bark is yellow.  Buckthorn leafs out earlier and holds leaves later in the fall than native trees.

Key ID traits:  Oval leaves with curved veins; spines on tips of twigs; yellow cambium layer under the bark.

Similar species:  Glossy buckthorn lacks the spines on twigs; leaves are not toothed, and leaves are hairy on underside.

Miscellaneous:  Common buckthorn was introduced for use as an ornamental.  It serves as the alternate host for crown rust of oats and the overwintering host for the soybean aphid. Aphid overwinters as eggs deposited at base of leaf buds.

Oval leaves with toothed margins, arching veins, and pointed tips.  Leaf arrangement is sub-opposite since they aren't truly opposite, but are not evenly spaced along the stem.

cluster of dark purple berries on female plant
Cluster of dark purple berries on female plant

spine on end of stem
Spine on end of stem


understory buckthorn with green leaves in contrast with senescing leaves of native trees
Buckthorn lining the edge of wooded area, the invasive species retains it leaves longer than the native overstory trees.