Ulmus 'Louis van Houtte'

Ulmus
'Louis van Houtte' in Christchurch Botanic Gardens, New Zealand
Cultivar	'Louis van Houtte'
Origin	Belgium

Ulmus 'Louis van Houtte' (Syn. Ulmus 'Vanhouttei') is believed to have been first cultivated in Ghent, Belgium circa 1863. It was first mentioned by Franz Deegen in 1886. It was once thought a cultivar of English Elm Ulmus minor 'Atinia', though this derivation has long been questioned; W. J. Bean called it "an elm of uncertain status". Its dissimilarity from the type and its Belgian provenance make the 'Atinia' attribution unlikely. Fontaine (1968) considered it probably a form of U. × hollandica.

The cultivar is named for the Belgian horticulturist and plant collector Louis Benoit van Houtte, 1810–1876.

When young, the tree has leaves entirely yellow, a colour retained throughout summer. However, as the tree ages, the colouring may begin a gradual reversion to green. The vertically fissured bark of mature trees is unlike that of English elm, with its squarish scaly fissuring. 'Louis van Houtte' has smaller leaves than the not dissimilar Ulmus glabra 'Lutescens' (Golden Wych Elm).

'Louis van Houtte' partially reverting, Brighton

'Louis van Houtte', Brighton (July 1992)

Foliage, botanic garden in Christchurch, New Zealand

'Louis van Houtte', Preston Manor, Brighton

Leaves, Christchurch, New Zealand

Bark, Christchurch, New Zealand

'Louis van Houtte' is vulnerable to Dutch elm disease (DED). A specimen at the Ryston Hall arboretum [3], Norfolk, obtained from the Späth nursery in Berlin before 1914, was killed by the earlier strain of DED prevalent in the 1930s, and two specimens planted at Kew Gardens in the Pagoda Vista succumbed very rapidly to the same fate in 1931. A mature specimen, which retained its yellow colouration in the crown, survived in Edinburgh's Royal Circus Gardens, before succumbing to the new strain of DED in the 1990s.

Before Dutch elm disease the tree was commonly cultivated in northern Europe. The Späth nursery of Berlin marketed it in the late 19th century as U. campestris Louis van Houtte. The tree was introduced under this name to the Dominion Arboretum, Ottawa, Canada in 1898. The tree appeared in the 1902 catalogue of the Bobbink and Atkins nursery, Rutherford, New Jersey, as Ulmus aurea Louis van Houtte, and in Kelsey's 1904 catalogue, New York, as U. 'Louis van Houtte'. It is less commonly cultivated in Australasia, where the golden wych elm Ulmus glabra 'Lutescens' has sometimes been mistakenly sold by nurseries under the name 'Louis van Houtte'. Three trees are known in the British Isles. The cultivar remains in commerce at a nursery in the USA.