Exotic Trees in the United States: Naturalized or Escaped from Cultivation

Trees species brought into an area where they did not ecologically develop or where they are not considered "native," are exotic trees. Many exotic trees are grown for food, ornamental, aesthetic, or other specialized uses. Sometimes these exotic trees escape cultivation and start to survive, grow, and reproduce on their own.

Self-replicating exotics can pose a threat to local ecological systems by replacing species and modifying the interconnections between species and site processes. In some cases, exotic species are considered to be an ecological asset, while in other situations, exotics trees are considered pests. This species list was prepared to assist foresters and restoration ecologists in recognizing exotic tree species by name. An asterisk following the common name signifies a tropical species.

Note that not all of these species are as interference prone (i.e. interference = competition + allelopathy) or as ecologically damaging as others. No priority is implied or given about the "pest potential" of any species. In each case, the tree species listed has reproduced in their new locations and could interfere with native systems or other exotic species already present. This is not an exhaustive list nor does it include large shrubs or bamboo.