Fraxinus excelsior, known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe and the British Isles.
Fraxinus, English name ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous, though a few subtropical species are evergreen. Fraxinus excelsior is a large deciduous tree growing to 12–18 m (39–59 ft) (exceptionally to 43 m or 141 ft) tall with a trunk up to 2 m (6.6 ft) (exceptionally to 3.5 m or 11 ft) diameter, with a tall, narrow crown. The bark is smooth and pale grey on young trees, becoming thick and vertically fissured on old trees. The species is widely cultivated and reportedly naturalised in New Zealand and in scattered locales in the United States and Canada. In the 13th-century Edda and other writing relating to Norse mythology, a mythological ash tree called Yggdrasil serves as the center of the world.