European buckthorn was brought to the US from Europe before the 1800s, as it was used for hedges, shelterbelt plantings, and wildlife habitat. The buckthorn is now found throughout southern Canada and the northeastern US, and it is still frequently sold in nurseries. It is a shrub with gray-brown bark and dark, glossy, broadly oval leaves with 3-4 pairs of curved veins. It usually grows between 5 and 15 feet high.
Buckthorns retard the composition and function of preexisting natural communities by simply outcompeting native plants and taking over. They are capable of altering ecosystems to the extent that birds and mammals that had formerly depended on the preexisting plants for food and shelter can no longer live in these overtaken areas. Controlling this invasive requires a persistent effort and a combination of pulling, hand cutting, girdling, burning, mowing, or applying of herbicides.