Fraxinus angustifolia, commonly known as the narrow-leaved ash, is a deciduous tree belonging to the Oleaceae family, which also includes olive trees and lilacs. It is widely distributed across southern and central Europe, north-west Africa and parts of western Asia, where it forms an important component of temperate and Mediterranean woodland ecosystems.
This species is one of the most common ash trees in the Iberian Peninsula and is well adapted to landscapes where seasonal water availability shapes the surrounding vegetation.
In northern Portugal, Fraxinus angustifolia is typically associated with riparian forests, river margins, wet meadows and valley bottoms, where soils remain deep and humid.
These ecological conditions occur in many parts of the Vale do Lourêdo landscape, where streams and seasonal watercourses create favourable environments for moisture-loving tree species.
The narrow-leaved ash is a medium-sized deciduous tree that can reach 20 to 30 metres in height. It develops a broad crown and a grey bark that becomes deeply fissured as the tree ages.
Its leaves are composed of several narrow lanceolate leaflets, a characteristic that gives the species its name. In early spring, before the leaves fully develop, the tree produces small wind-pollinated flowers that later give rise to winged seeds known as samaras.
Ash trees such as Fraxinus angustifolia play a crucial role in riparian ecosystems, helping stabilize riverbanks and providing habitat for numerous insects, birds and other wildlife.
In traditional rural landscapes of northern Portugal, ash trees are also part of historic agro-pastoral systems, where they coexist with meadows, hedgerows and mixed woodland.