The Caucasian Wing-nut (Pterocarya fraxinifolia)
There are two good examples of these trees in Dulwich Park, on the grass between the lake and the southern carriageway. They were found in the Caucasian mountains, in what was then Persia, in 1782, brought to France and then to England.
The ones in the park are multi-stemmed, low spreading trees which sucker freely, but they can grow to 30 metres in damp places. The compound leaves consist of up to 25 large floppy leaflets and the grey bark has coarse ridges. The distinctive feature of these trees is their seed pods. They start as yellow catkins (both male and female flowers are found on the same tree) in the spring and develop into long dangling strings of pale green seed pods like beads on a necklace. Each seed is contained in a nut with a broad wing, hence the tree’s name. The pods can often be seen, brown and withered, in winter.
Caucasian Wing-nuts are quite frequently planted in parks nowadays, because of their toughness and vigour.
Stella Benwell Trees Committee