Fraxinus ornus (manna ash or South European flowering ash) is a species of Fraxinus native to southern Europe and southwestern Asia. Fraxinus ornus is a medium sized deciduous tree growing to 15–20 m tall with a trunk up to 1 m diameter. The bark is dark grey, remaining smooth even on old trees.
The leaves are in opposite pairs, 20 - 30 cm long. The flowers are produced in dense panicles 10–20 cm long after the new leaves appear in late spring, each flower with four slender creamy white petals 5–6 mm long, they are pollinated by insects. The fruit is a slender samara 1.5 - 3 cm long, the seed 2 mm broad and the wing 4–5 mm broad, green ripening brown.
Fraxinus ornus is frequently grown as an ornamental tree in Europe north of its native range, grown for its decorative flowers. A sugary extract from the sap is extracted by making a cut in the bark, this was compared in late mediaeval times with the biblical manna, giving rise to the English name of the tree. In fact, the sugar mannose and the sugar alcohol mannitol both derive their name from the extract.