The corktree was introduced to the U.S. in the 1850s and by the early 1900’s it was planted throughout the northeastern portion of the country in boulevards, parks and residential yards. It adapted so well to its new environment that it became naturalized to forested areas, often outcompeting native vegetation. Some states have placed it on their invasive species list, prohibiting people from planting or selling it. This tree also has juicy, dark fruits that ripen in mid-summer. However, these berries are less nutritious than the nuts produced by trees it is outcompeting, such as oaks and hickories, produce, therefore affecting local wildlife. This tree is dioecious, meaning that male and female flowers are found on separating plants. Therefore, by planting only male trees, the possibility of reproduction is eliminated.