Ash
Fraxinus excelsior — known as the ash, or European ash or common ash to distinguish it from other types of ash — is a species of Fraxinus native to most of Europe from Spain to Russia, with the exception of northern Scandinavia and southern Iberia. It is also considered native in southwestern Asia from northern Turkey east to the Caucasus and Alborz mountains.
Source: http://en.wikipedia.org/wiki/Fraxinus_excelsior
Photo by: Andrew CC BY 2.0
Willow
Salix alba (white willow) is a species of willow native to Europe and western and central Asia. The name derives from the white tone to the undersides of the leaves.
Source: http://en.wikipedia.org/wiki/Salix_alba
Photo by: André Karwath CC BY-SA 2.5