Tree-of-heaven, also known as ailanthus, Chinese sumac, and stinking sumac, is a deciduous tree in the mostly tropical quassia family. Mature trees can reach 80 feet in height. Ailanthus has smooth stems with pale gray bark and twigs which are light chestnut brown, especially in the dormant season. Its large compound leaves are 1-4 feet in length, alternate, and composed of 10-41 smaller leaflets. Each leaflet has one or more glandular teeth along the lower margin. The leaf margins are otherwise entire or lacking teeth. Ailanthus is a dioecious (“two houses”) plant meaning that male and female flowers occur on separate plants. Flowers occur in large terminal clusters and are small and pale yellow to greenish. Flat, twisted, winged fruits each containing a single central seed are produced on female trees in late summer to early fall and may remain on the trees for long periods of time. The wood of ailanthus is soft, weak, coarse-grained, and creamy white to light brown in color. All parts of the tree, especially the leaves and flowers, have a nutty or burned nut odor.

Look-alikes: It is important not to confuse native shrubs and trees with ailanthus. Native sumacs (Rhus) and trees like ash (Fraxinus), hickory (Carya), black walnut, butternut and pecan (Juglans) can be distinguished from tree-of-heaven by having completely serrated (toothed) leaf margins.


Tree-of-heaven is a fast-growing tree and a prolific seeder, that  can  take over sites, replacing native plants and forming  dense thickets. Ailanthus  also produces chemicals  that prevent the establishment of other plant species nearby. Its root system may be extensive  and has been known to cause damage to sewers and foundations. 

Ailanthus (tree-of-heaven) stand near the Wrighton Road entrance of the Glendening Preserve.

 How You Can Help:

The aggressive nature of tree-of-heaven makes it difficult to control by mechanical/hand removal. When disturbed, the roots resprout abundantly.

Volunteers can be of great assistance in late summer/early fall when female trees are producing seeds. One tree can make up to 325,000 seeds. Bagging and disposing of seeds can help reduce the spread of this NNI.

For full species information visit the Plant Conservation Alliance's LEAST WANTED page.















The papery seeds of a female ailanthus tree. A stand grows along the edge of a neighbor's field.