Buckthorn & Other Invasive Species

Species that have been introduced, or moved, by human activities to a location where they do not naturally occur are termed 'exotic,' 'non-native,' 'alien,' and 'non-indigenous.' Non-native species are not necessarily harmful, but when non-native species cause ecological or economic problems, they are termed 'invasive' or 'harmful exotic species.'

Common Buckthorn (Rhamnus cathartica) Common buckthorn are aggressive invasive deciduous shrubs or small trees reaching heights of over 20 feet. These plants spread from seed dispersal by birds and animals. Buckthorn was first brought to Minnesota from Europe in the mid-1800s as a very popular hedging material. Shortly after its introduction here, it was found to be quite invasive in natural areas. Common buckthorn leaves are oval, rounded or pointed at the tip, dark glossy green, and remain green late into fall. In the fall, small yellow-green flowers cluster at the base of leaves and produce small black fruit on female trees. It has gray to brown bark, rough when mature, inner bark is yellow and heartwood is pink-orange. Buds and leaves are opposite and twigs often end in sharp, stout thorns.

Other Invasive Species to Minnesota The Minnesota Department of Natural Resources (DNR) has a list of aquatic animals, aquatic plants, terrestrial animals, and terrestrial plants that are invasive to Minnesota. Click on the link below to access this list: Minnesota DNR Invasive Species List The Community Forestry Resource Center has also developed a list of invasive plant species, please click on the link below to access this document: Invasive Plant Species of Minnesota Forests