Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Sapindales
Family: Simaroubaceae
Genus: Ailanthus
Species: A. altissima
Binomial name: Ailanthus altissima
Synonym: Ailanthus glandulosa
Common names: Tree of heaven, Ailanthus, Chinese sumac, Stinking shumac, Tree from hell, Laquer tree, Copal tree, Varnish tree, Rotting carrion tree, Baked sewage tree, Kerosene tree, Junk tree, Stink tree.

Ailanthus altissima is a deciduous tree native to both northeast and central China, as well as Taiwan. It can reach heights of between 17 and 30 metres. It has pale-striped grey bark and the ends of the branches become pendulous.
The tree has leaves made up of 11-25 alternating hairless leaflets (7-17cm long x 3-7.5 cm wide) with bluish green undersides and 1-3 coarse teeth near their bases.

The leaflets have glands which give the tree a distinguishing strong odour, especially when the leaves are crushed. The odour is often likened to peanuts, cashews or rotting cashews.
In New Zealand during December to January clusters of small yellow-green flowers (2.5-4 mm long petals) develop. The female flowers are followed by dry pink to tan fruits that have a single winged seed in their centres. The shape of the dried fruit resembles a propeller.

Ailanthus altissima is classed as an invasive tree in and is listed legally as an unwanted organism by Biosecurity New Zealand. They suggest one should contact one's regional council to determine the status of this species and responsibility for control and/or advice on control.
Ailanthus altissima is a prolific seeder which grows rapidly forming dense thickets of suckering shoots. It will out-compete native species for sunlight and space. It is spread by seed and by suckers. Cutting down the main trunk encourages the aggressive root system to sucker over large areas. It will resprout from stumps and root fragments. The roots will block drains.
Ailanthus altissima produces a toxin in its bark, roots and leaves that accumulate in the soil to prevent other plant species establishing near it. It inhabits roadsides and waste places.
All parts of the plant are poisonous if ingested.

A stand of Ailanthus altissima
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Young sapling.
1-Tree of Heaven Re-sprouting.jpg

A dense thicket of suckering shoots
1-Ailanthus-altissima 1.jpg

The flowers.December to January.

Unripe fruit.
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A female tree bearing a heavy load of fruit. 

The dried fruit with one seed inside.
1-Ailanthus altissima seeds.jpg.

A video on this invasive tree.

Thanks to Wikipedia for text and information: