This very rare maple is another example of the genus in the maple collection in Belfast Botanic Gardens. It is a small, slow-growing tree from Northern China and Korea with distinctive leaves divided into three separate leaflets and pale grey-brown flaking bark. Like Acer maximowiczii which is close to it in the Botanic Gardens, it usually has spectacular autumn colour. The flowers are in threes, hence the species name. It was introduced in 1923, but rarely seen outside of arboreta and Botanic Gardens. Mature examples are in the Arnold Arboretum in Boston. RHS award of garden merit. 
The Belfast Botanic Gardens example was near the path from the Botanic School gate to the Palm House. Unfortunately this tree was in the path of a fallen oak in 2021 and was removed in the clean-up. We hope a replacement for this attractive tree can be found.

Photos taken in Belfast Botanic Gardens in 2018. Copyright: Friends of Belfast Botanic Gardens.