The tree is noted for its fastigiate shape, and foliage which turns orange or red in autumn where planted on acid soils, not yellow as with the species.
The tree is also to be found in France, Germany, the Czech Republic, Hungary and Poland.
Having cleared the Quarantine Laboratory, the Caldwell Maple is now being grown by Schmidts' Nurseries in Oregon where its remarkable clean growth when compared to their other Field Maples is cause for celebration.
The cultivar was originally known as 'King Canute' until 1983 when Donovan Caldwell Leaman changed the name in honour of his cousin and business partner Bill; King Canute seated on his throne was the emblem and trademark of Caldwell & Sons Ltd Nurseries, Knutsford.
The Height Champion Tree, planted in Winter 1987/88 atop Alderley Edge, Cheshire was measured in December 2019 as 16.3 metres (52 feet, 11 inches) Fittingly, the Girth Champion Tree, one of the original layers, was planted in Knutsford.