Hornbeam or Maple?
The tree in front of you looks very like a hornbeam, (Carpinus betulus), with beautifully understated, ovate, conspicuously parallel ribbed leaves but examine how the leaves are arranged. If it were a hornbeam the leaves, (or buds in the winter months), would be arranged alternately.
This rare plant is actually a maple, Acer carpinifolium and the buds or leaves, as with all maples are perfectly opposite to each other, each pair of leaves being at 90 degrees to the pairs of leaves above and below them.
Acer carpinifolium is rare in cultivation. It was introduced from Japan by Charles Maries in 1879 who introduced lots of fine plants to the UK, notably the familiar Viburnum plicatum 'Mariesii'.
A small tree in cultivation, the Hornbeam Maple has lovely autumn colours. Acer carpinifolium is dioecious, i.e., the male and female flowers are born on separate plants.
Extract from an information poster in our arboretum