Chicago Botanic Garden

Plant Science — Conservation

Invasive Plants in the Chicago Region

Trees

 

Plants with a dash under the "alternatives" column are not commonly used ornamentally. You can find more information on alternatives at Illinois' Best Plants or www.bestplants.org.

TREES
Species Common Name Status Alternatives
Acer ginnala Amur maple P Acer rubrum (red maple), Quercus alba (white oak)
Acer platanoides Norway maple R species
E cultivars
Acer x freemanii 'Marmo' (Marmo maple), Acer miyabei (Miyabe maple), Acer rubrum (red maple), Quercus alba (white oak)
Ailanthus altissima Tree-of-heaven R Fraxinus spp. (ash species)
Alnus glutinosa European black alder P species
E cultivars
Celtis laevigata (sugarberry), Celtis occidentalis (common hackberry), Nyssa sylvatica (black tupelo)
Malus spp. (crabapple) Crabapple E Crataegus spp. (hawnthorn species), Prunus serotina (black cherry)
Morus alba Mulberry P Crataegus spp. (hawthorn species), Prunus serotina (black cherry)
Phellodendron amurense (except male cultivars) Amur corktree R Acer rubrum (red maple), Phellodendron amurense (male cvs.), Quercus alba (white oak)
Populus alba White poplar P Betula nigra (river birch), Catalpa speciosa (Northern catalpa), Platanus occidentalis (American sycamore)
Prunus mahaleb Mahaleb cherry P Crataegus spp. (hawthorn species), Prunus serotina (black cherry)
Pyrus calleryana Callery ornamental pear W Chionanthus virginicus (fringetree), Crataegus spp. (hawthorn species), Prunus serotina (black cherry)
Robinia pseudoacacia Black locust R species
E cultivars
Catalpa speciosa (Northern catalpa), Gleditsia triacanthos (honeylocust)
Ulmus pumila Siberian elm R Dutch-resistant cvs. of Ulmus americana (American elm)

Chicago Botanic Garden Conservation Science Department Status:

R = Remove as soon as possible, including all cultivars, and/or do not add to collection in future;
P = Phase out (species that pose a lesser invasive risk, form significant structural features in landscape, and will be time-consuming to replace will be phased out over a five- to ten-year period);
E = Evaluate species and cultivars, then remove invasive taxa;
W = Watch list (taxa not posing a serious invasive risk in the Chicago area currently, but may do so in the future).