Ostrya carpinifolia, the European hop-hornbeam is superficially very similar to the Eastern hop-hornbeam Ostrya virginiana an avenue of which have recently been planted between the PEC and the car park. The European hop-hornbeam is native from SE France to the Caucasus Mountains. The leaves of the hop-hornbeams are also very similar to the hornbeams (Carpinus genus - eg Carpinus betulus, the common hornbeam native to England, but not to Ireland) as the latin species name carpinifolia suggests.
The European hop-hornbeam makes a medium sized tree to about 25m and can be seen as a handsome street tree in towns in southern France. The young tree in Belfast Botanic Gardens, close to the bandstand, is producing catkins, and produced female flowers in 2022. It is, perhaps, unlikely to set viable seed in this country.