Fraxinus excelsior – European ash
The European ash is a large deciduous tree commonly found in our woods, parks, hedgerows and urban environments. There are an estimated 11 million mature ash trees in Scotland.
The leaves of an ash tree comprise a single stem, with three to six pairs of opposing leaflets with a single terminal leaflet at the end. The leaves follow the movement of light throughout the day and sometimes the whole crown can appear to be leaning towards the sun. Once pollinated, female ash flowers develop ‘winged’ seeds, known as ‘keys’, which form in characteristic bunches and disperse with the wind to create new saplings.
The tree’s silvery grey bark is smooth when young and develops cracks and fissures in maturity, providing a perfect habitat for lichen, moss and insects. The leaves fall early in the autumn, often when still green, decomposing quickly and providing a fertile habitat for fungi, wildflowers and other woodland plants. Ash can be identified in winter by its smooth twigs with distinctive black, velvety buds. Why is ash so important? Almost 1000 species are known to use the tree including several that rely wholly on it for their survival. There are 536 species of lichens that live on ash, including 220 that are nationally rare and 6 which have special protection under the UK Wildlife Countryside Act 1981.
