common buckthorn

Rhamnus cathartica L.

Description:

Leaves & stems: Ovate or elliptic, with prominent veins curving toward tip. Mostly opposite leaves, 1-2.5” long, with tiny teeth. Leaves remain on plants and stay green into fall. Bark is gray to brown with prominent light-colored lenticels. Cut bark exposes an orange inner cambium layer.

Flowers: Inconspicuous, small and clustered in leaf axils. Fragrant, greenish-yellow, 4-petaled flowers that bloom in spring.

Fruits & seeds: Abundant clusters of round, black, pea-sized fruit. Ripen on female plants in late summer. Dispersed by birds and mammals. Fruits remain on plants into winter after all the leaves have fallen.

Roots: Extensive, black fibrous root system.

Similar species: Glossy buckthorn (Rhamnus frangula; invasive) is similar to common buckthorn. Leaves are mostly opposite, with greater number of veins. Upper surface of leaves are shiny with undersides dull.

Alder buckthorn (Rhamnus alnifolia; native) is under 3’ tall with thornless twigs. Lance-leafed buckthorn (R. lanceolata; native) is less than 6’ tall, found in wet areas and on dry limestone slopes, and has alternate leaves, 2-6” long, gradually tapering to a point at the tip. Carolina buckthorn (R. caroliniana; native), found in the southern Midwest, is 10-30’ tall with toothed, mostly alternate leaves, 2-3” long.

Source:  Wisconsin DNR Invasive Species website.

Locations:

Found in woodlands, wetlands and prairies.

Impact:

Common buckthorn has several several serious impacts on your property:

• Creates dense thickets where nothing can grow beneath it.
• Produces a chemical called emodin into the soil from its roots. Emodin suppresses growth of competing plants, negatively impacts insect and amphibian populations, and changes the soil chemistry.
• Serves as host plant for soybean aphids and crown rust fungus.

common buckthorn