Ailanthus altissima

The tree of heaven in the Simaroubaceae family is native to both northeast and central China, as well as Taiwan. The roots, leaves and bark are still used today in traditional Chinese medicine.

• Leaves are alternate, pinnate, to 60 cm long with 15 or more pairs of leaflets, each up to 12 cm long and 5 cm across. Leaves are slightly asymmetrical, with distinguishing small 'tips' sticking out on either side of the base of the leaf.
• The species is dioecious (having male trees and female trees). In flowering, male trees produce many more flowers than female trees, so stand out in July. However, by August the seed pods on the female trees are readily visible as clusters of red pods with white undersides, and each cluster can contain hundreds of seeds.
• The seeds borne on the female trees are 5 mm in diameter and are samaras 2.5 cm long and 1 cm broad; they can persist on the tree until the next spring when new leaves are out.
• Twigs have a soft foam pith; leaf scars are horseshoe-shaped, with 6–8 vascular bundles forming an upward-facing 'C' shape.