The Tree of Heaven Ailanthus altissima, native to northern and central China, was introduced to Britain in 1751. It was planted extensively in London Squares and elsewhere in parks, streets and gardens. It is now very common in urban areas and has spread naturally in the warmer parts of the USA by colonising waste ground. The leaves have a characteristic bad odour when crushed. At first sight the tree looks like an Ash but closer examination of the leaves shows the difference.

A Tree of Heaven in full leaf in August.

A Tree of Heaven in late October.

Each leaf has 11 to 25 leaflets. It is a pinnate leaf. At first sight the leaf looks like that of the Common Ash. Click HERE for a photo of a Common Ash leaf. May also be confused with the pinnate leaf of the Stag’s horn Sumach but its leaves are toothed.

Each leaflet is smooth-edged but has a single tooth at the base of the leaf.

The male flowers come out in July.


The fruit hangs, in the form of keys, like this in October. They look like Common Ash keys except for their colour.

The bark has vertical “snakes” like this