Quercus rysophylla Weath.
Mexican oak or loquat oak
The tree tag number relates to the black tree-maintenance tags, usually fixed on the trunk, 2 to 3m above ground level.
This is an evergreen oak from Mexico, first described in 1910. It is rare in cultivation, introduced to horticulture by Sir Harold Hillier from the Horsetail Falls above Monterrey in Mexico, as late as 1979. Its most distinctive feature is the bright reddish young leaves in spring. The mature leaves are a bright glossy green. It seems to be quite fast growing, but its final height in Ireland is not yet known.
The Belfast Botanic Gardens specimen is planted close to the Ulster Museum as shown below. Other specimens are planted in the Hillier Gardens and Kew Gardens.
The Belfast tree is grafted (probably onto Q. cerris) and from time to time produces shoots from the rootstock which need to be removed.
Photos taken in Belfast Botanic Gardens. Copyright: Friends of Belfast Botanic Gardens.