The wych elm cultivar Ulmus glabra Huds. 'Superba', Blandford Elm, with unusually large leaves, was raised by Gill's of Blandford Forum, Dorset, in the early 1840s as Ulmus montana superba and was quickly distributed to other UK nurseries. It was confirmed as a form of wych, and first described by Lindley in The Gardeners' Chronicle, 1845, later descriptions being added by Gill (1845) and Morren (1848), who called it U. montana var. superba. Morren had adopted the name 'Superba' from the Fulham nurseryman Osborne in 1844, who supplied him with the tree – presumably one of the nurseries supplied by Gill. Morren states that 'Superba', already in cultivation in England, was introduced to Belgium by Denis Henrard of Saint Walburge, Liège, that in 1848 it had been present in Belgium for only three years, and that this variety was the one described as 'Superba' by Osborne, whom Henrard had visited at his nursery in Fulham in September 1844. 'Blandford Elm', with leaves of the same dimensions, was soon for sale in the USA (see 'Cultivation').
The Späth nursery in Berlin supplied a large-leaved U. montana superba from 1885 to the 1930s. H. Jensen examined the tree at Späth's nursery and confirmed (1912) that it was identical to Morren's Ulmus montana superba. Späth's catalogue of 1911–12, however, had erroneously claimed that a U. praestans E. Schoch was synonymous with Morren's U. montana superba. Hartwig, who received specimens of U. praestans from Kiessling of the Magdeburg city nursery in 1908, said (1912) that "Ulmus montana superba, supposedly the same [as U. praestans], looks quite different when young, being wide with large, broad, dull green leaves, whereas ... U. praestans show an elongated medium-sized shiny green leaf and densely pyramidal crown". He concluded that U. praestans was not Ulmus montana superba. Späth admitted the error in an article in Möller's Deutsche Gärtner-Zeitung (1912), where he stated that U. praestans E. Schoch was an Ulmus × hollandica hybrid, and implied that Morren's tree was a form of U. montana (wych elm). In later catalogues the nursery distinguished between Morren's Ulmus montana superba and the hybrid U. praestans E. Schoch (for which he adopted Henry's synonym Ulmus superba Henry), marketing both cultivars in the post-war period.
Späth was not the only botanist to confuse wych and hybrid 'Superba'. Though Loudon in his description (1838) of Canterbury Elm, Ulmus montana glabra major, had made no reference to large leaves, Boulger tentatively (1881) and Green more confidently (1964) equated Canterbury Elm with Morren's U. montana var. superba, a synonym not included in Rehder's lists (1915 & 1949). Loudon's description of Canterbury Elm, a fast-growing hybrid like Huntingdon Elm, holding its leaves late, does, however, match descriptions of U. × hollandica 'Superba' [U. praestans].
Description
Descriptions of 'Superba' cultivars vary, as do herbarium specimens, confirming that more than one clone has been given the name. Gill's Ulmus montana superba had very large leaves, long by wide. Osborne and Morren's Ulmus montana var. superba likewise had very large wych-like leaves, to 26 by 15 cm, with a tapering tip to 3–4 cm long. The matching names, measurements and dates confirm that Gill's, and Osborne and Morren's, trees were the same clone. An 1880 herbarium specimen showing a large-leaved wych cultivar at Kew Gardens, labelled U. montana superba, has dimensions similar to those given by Gill and Morren (juvenile elm leaves may be larger than those of mature canopy-leaves). The Ulmus 'Superba', 'Blandford Elm', in the 1902 catalogue of the Bobbink and Atkins nursery, Rutherford, New Jersey, was described as "a noble tree of large size and quick growth", with "large dark green foliage and smooth, grayish bark" (presumably in young specimens).
Etymology
Morren states that 'Superba' was so called "parce qu'en effet cette variété l'emporte sur les autres par sa beauté" [:because indeed this variety surpasses others in beauty].
Pests and diseases
With the exception of Exeter Elm and dwarf wych, U. glabra Huds. cultivars are not noted for any resistance to Dutch elm disease.
Cultivation
An 1880 Kew Gardens herbarium specimen, from one of the arboretum's own trees, labelled U. montana var. Superba and matching Lindley's description, confirms that Gill's tree was present at Kew (see 'External links'). Mid 20th-century herbarium specimens from the Wageningen Aboretum, The Netherlands, show a wych cultivar there "formerly labelled Ulmus × hollandica 'Superba'".