(aka Chinese Sumac)

(Ailanthus altissima)


Leaves (showing leaflets)



Bark                               Seeds

Family: Quassia family- Simaroubaceae



The species tolerates a wide range of

conditions but does best in mesic

environments with soils rich in loam.

It is common in disturbed sites

(considered a weed tree) and also in

urban and suburban areas in alleys,

along and through cracks in sidewalks,

parking lots, and streets.  Thus, it can

be found in sites unsuitable for other

trees. Tree-of-heaven occurs, as well, in

agricultural and forest areas provided

there is not excessive shading.



Tree-of-heaven is native to eastern and

central China, Taiwan, and northern Korea.

It is an exotic and was introduced into the

United States in 1784 and is now found

across the continental U.S, the eastern

third of Canada, as well as Hawaii.,r:0,s:0,i:86&tx=100&ty=85


Physical Characteristics:


This is a rapidly growing deciduous tree

that can attain a height of 80 feet and a

diameter of 6 feet.



The alternate, large pinnately compound

leaves (on stalks of 1- 3 feet) each have

10 to 41 smaller ovate-lanceolate leaflets

2-7 inches long and 1-2 inches wide. Leaflets

are toothed only at their base and underneath

have a small gland at their tip. They are dark

green in color and, upon crushing, have an

odor much like the smell of rotting peanut

butter or rancid buttered popcorn.



Flowers are small with a pale yellow-greenish

to a red color and are bunched into large

clusters on the end of shoots. Flowers are

typically unisexual and male (foul smelling)

and female flowers occur on different

individuals (dioecy). The flowers smell like




The samaras, or winged fruits, are produced

in the summer and turn yellow to rosy red

as they ripen. The samaras grow to 1.5

inches long. The fruits last on the tree

from the summer through the winter.

The wing of the fruit is twisted and this

enables the fruit to spin rapidly when

falling from the tree to the ground.



This tree has pale gray colored bark and

the twigs of the tree are chestnut brown.

It possesses lighter vertical streaks. The

wood of the tree is soft and flaccid, having

a creamy white to a light brown color.



The “tree-of-heaven” has a very strong

root supporting system. It produces

horizontal roots capable of sprouting. With

a vast spreading root system, root sprouts

may appear as far as 50 to 90 feet from the

parent stem.


Interesting Facts

Ailanthus altissima is an agricultural pest

and often ecological threat. The tree grows

rapidly and is able to invade areas while

replacing native plants and creating dense



This species produces an “allelopathic”

chemical known as ailanthone that

hinders the growth of other plant species.


Roots can spread over a wide area and can

damage sewers and foundations.


It is one of the most pollution-tolerant

species of trees and resists high levels of

sulfur dioxide, ozone, and mercury.


Trees can also survive low phosphorous and

high salinity soil levels and pH levels as low

as 4.1. The ability of roots to store

considerable water aids in drought



Ailanthus altissima was first introduced

To the United States by a gardener from

Philadelphia, PA in 1784. In the 19th

century availability from nurseries and

transport and planting by Chinese

immigrants (esp. those participating in

the California goldrush) facilitated its

spread across the U.S..


The plant is also a pest in Australia and

New Zealand.


The tree-of-heaven is mentioned in

several ancient Chinese medicinal texts

because it was believed to cure mental

illness as well as baldness. Parts of

the tree are still used in traditional

Chinese medicine as an astringent.


All parts of this tree, especially the

leaves and flowers have a nut-like or

burned nut odor.


Similar species

Black Walnut (Juglans nigra)


The compound leaves of this tree look

similar to those of Ailanthus altissima

but the leaflets are finely serrated along

their margins. The fruit of black walnut

is green, large, and ball-shaped nut unlike

the samara of the tree-of-heaven, and the

bark is dark and rough.




Additional References

Albright, T. P., Chen, H., Chen, L. and Guo, Q.  2010. The ecological

niche and reciprocal prediction of the disjunct distribution of an

invasive species: the example of Ailanthus altissima. Biological

Invasions. 12: 2413-2427. 


De Feo, V., De Martino, L., Quaranta, E. and Pizza, C. 2003. Isolation

of phytotoxic compounds from tree-of-heaven (Ailanthus altissima

Swingle). Journal of Agricultural and Food Chemistry. 51: 1177-1180.


Hunter, J. C. 1995. Ailanthus altissima (Miller) Swingle: its biology and

recent history. California Exotic Pest Plant Council News. 3: 4-5.


Knapp, L. B.; Canham, C. D. 2000. Invasion of an old-growth forest in

New York by Ailanthus altissima: sapling growth and recruitment in

canopy gaps. Journal of the Torrey Botanical Society. 127: 307-315.


Swan, C. M., Healey, B., Richardson, D. C. 2008. The role of native riparian

tree species in decomposition of invasive tree of heaven (Ailanthus altissima)

leaf litter in an urban stream. Ecoscience. 15: 27-35.