The common or European ash is a deciduous tree that grows to a height of 20 to 40 metres. The trunk is straight with smooth, grey bark at first that later develops shallow fissures and turns grey-black. The leaves are composed of pairs of leaflets, each up to 10 to 12 centimetres long and with serrated edges. The leaves appear quite late, the latest of all European trees, and they are the first to fall in autumn, dropping while still green. The fruits (achenes) contain a single seed, each one set in a long narrow brown wing. The wings hang in bunches and are known as “ash keys”.
The common ash is native to most of Europe, growing from lowland to mountain regions. It is commonest in flood-plain forests.