Ulmus × hollandica 'Superba'

The hybrid elm cultivar Ulmus × hollandica 'Superba', once commonly known in the UK as the Canterbury Elm, is one of a number of hybrids arising from the crossing of the Wych Elm U. glabra with a variety of Field Elm U. minor. Identified by Morren as U. montana (: glabra) var. superba in Jour. Agric. Prat. Belg.: 411 1848 and much later by Krüssmann in Handb. Laubgeh. 2: 537, 1962 as a cultivar.^[1]

Description

'Superba' is a rapidly growing, narrow, pyramidal tree with smooth bark and steeply ascending branches, bearing large leaves very similar to the Wych Elm but with long stalks. The flowers too resemble those of the Wych Elm.

Pests and diseases

The tree is very susceptible to Dutch elm disease.

Cultivation

'Superba' was reputed by Louis Späth to have been much valued as a street tree, notably in Magdeburg, Germany. It was cultivated in the UK by Masters at Canterbury in the early 19th century, where it became known as 'Master's Canterbury Seedling' or simply the 'Canterbury Elm', and later, confusingly, as U. montana (: glabra) 'Major'.^[2] 'Superba' was reintroduced to the UK at Kew Gardens in 1900, obtained from the Späth nursery in Berlin, and remains represented by a specimen at Wakehurst Place donated in 1949; it survives by being treated as a hedging plant, too low to attract the attentions of the Scolytus beetles which act as vectors of Dutch elm disease.

It is not known whether 'Superba' was introduced to North America. An elm identified as 'Superba' was photographed at the Ellwanger and Barry nursery at Mount Hope, Rochester, New York, c. 1900. However, the photograph is also endorsed 'Belgian Elm', which it more strongly resembles.

Synonymy

• Ulmus montana (:glabra) var. major Masters: Loudun, Arb. Frut. Brit. 3: 1398, 1838.
• Ulmus montana (:glabra) 'Superba' Lavallée, in error for 'Cornuta'.^[1]
• Ulmus superba A. Henry

Accessions

Europe

• Wakehurst Place Garden Wakehurst Place. Acc. no. 1949–42304

References