Sharp-tooth buckthorn | The Morton Arboretum

Sharp-tooth buckthorn (Rhamnus arguta) is an exotic weed and invasive plant in Illinois. This shrub spreads by seed. It commonly grows in wooded areas and disturbed sites. It is found within the Midwest (USDA Zones 5-7). The shrub typically grows to about 10 feet tall. The bark is dark brown in color, and there are thorns along the stem. The simple, dark green leaves are heavily serrated around the edges, with less distinct venation than common buckthorn. The small flowers are white to light green, and the berries are dark blue.

The quick and easy spreading habits of buckthorns allow the shrub to develop dense infestations. This can reduce the amount of space accessible by native plants. Additionally, it develops foliage that lasts longer than many other plants, restricting sunlight for groundcovers and shorter plants. As an alternative, nannyberry (Viburnum lentago) is a good option.

There are a number of native and non-native species that could be used in place of sharp-tooth buckthorn. To find suitable replacements, go to The Morton Arboretum’s tree and plant finder. Before purchasing or planting, be sure to check for any local or state guidelines, and ensure that it is suitable for its habitat by reviewing planting considerations or by finding it in the USDA Plants Database.

More Information

Size and Method of Spreading

Sharp-tooth buckthorn is a small shrub that typically grows to about 10 feet tall. The branches are long and far-reaching.

Bark Color and Texture

The bark is dark brown in color, while newer shoots have a red coloration. The texture of the bark is smooth, with medium-sized thorns throughout the stems.

Leaf Description

The simple, dark green leaves have an opposite leaf arrangement, sometimes with a slight gap in the spacing (sub-opposite leaf arrangement). The leaves are about 1-3 inches in size, with an oval (ovate) shape and serration around the edges.

Flower Description

The small flowers (florets) of sharp-tooth buckthorn are arranged in a group that join together to create a flat-topped cluster (umbels). The flowers are white to light green in color.

Fruit Description

Sharp-tooth buckthorn has fruits with a singular seed, surrounded by a fleshy covering (drupe). They are green in color, and less than 1 inch in size.