Ulmus glabra 'Superba'

Last updated
Ulmus glabra 'Superba'
Belgium Elm at Ellwanger & Barry, Rochester NY.jpg
'Superba', Mount Hope, Rochester, New York, c.1900
Species Ulmus glabra
Cultivar 'Superba'
OriginEngland

The wych elm cultivar Ulmus glabraHuds. '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. [1] It was confirmed as a form of wych, and first described by Lindley in The Gardeners' Chronicle , 1845, [2] later descriptions being added by Gill (1845) [1] 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. [3] 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, [3] and that this variety was the one described as 'Superba' by Osborne, whom Henrard had visited at his nursery in Fulham in September 1844. [4] 'Blandford Elm', with leaves of the same dimensions, was soon for sale in the USA (see 'Cultivation').

Contents

The Späth nursery in Berlin supplied a large-leaved [5] U. montana superba from 1885 [6] to the 1930s. [5] [7] H. Jensen [note 1] examined the tree at Späth's nursery and confirmed (1912) that it was identical to Morren's Ulmus montana superba. [8] Späth's catalogue of 1911–12, however, had erroneously claimed that a U. praestansE. Schoch was synonymous with Morren's U. montana superba. [9] 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. [10] Späth admitted the error in an article in Möller's Deutsche Gärtner-Zeitung (1912), [11] where he stated that U. praestansE. 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. praestansE. Schoch (for which he adopted Henry's synonym Ulmus superbaHenry), marketing both cultivars in the post-war period. [7]

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, [12] [13] Boulger tentatively (1881) [14] and Green more confidently (1964) [15] equated Canterbury Elm with Morren's U. montana var. superba, a synonym not included in Rehder's lists (1915 & 1949). [16] [17] 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, 10 in (25 cm) long by 6 in (15 cm) wide. [1] 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. [4] 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). [herb 1] 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). [18]

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]. [3]

Pests and diseases

With the exception of Exeter Elm and dwarf wych, U. glabraHuds. 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'". [herb 2] [herb 3] [herb 4]

Ulmus montana superba, 'The superb-leaved elm', appeared in the catalogues of Hovey's nursery of Boston, Massachusetts, from the 1850s. [19] 'Blan[d]ford Elm (superba)', with "remarkably large leaves", appeared in the 1868 catalogue of the Mount Hope Nursery (also known as Ellwanger and Barry) of Rochester, New York; [20] [21] by the 1880 catalogue it was listed as U. montana var. superba (Blandford Elm), "A noble tree of large size and quick growth; foliage large and dark green; bark smooth and grayish". [22] Under the same name and description it appeared in the catalogues of the Bobbink and Atkins nursery, Rutherford, New Jersey, [18] [23] and in Kelsey's 1904 catalogue, New York. [24] The absence of Späth's names from the Bobbink and Atkins and the Kelsey lists and their use of 'Blandford Elm' suggest that the cultivar was Gill's clone.

A cultivar listed in 2008 as Ulmus × hollandica 'Blandford' by the Urban Forestry Administration of the District Department of Transportation in Washington, D.C., as one of its 'street trees', is likely to have been Blandford Elm misnamed as a hybrid, or hybrid 'Superba' misnamed 'Blandford'. [25]

Given Späth's pre-1912 naming error, it is not clear whether one planting of U. montana superba at the Dominion Arboretum, Ottawa, Canada, in 1896, sourced from Späth, [26] was the wych or the hybrid 'Superba'. The specimen (no. 42304) maintained as part of a low hedge at Wakehurst Place, Sussex (2020), grown from a cutting from Ottawa donated in 1949, is, however, listed as the hybrid 'Superba', [27] suggesting that 1896 Ottawa planting may likewise have been the hybrid.

Notable trees

A large-leaved elm described as Ulmus campestris 'Superba' obtained from Louis van Houtte of Ghent, Belgium, before 1841 was photographed at the Ellwanger and Barry nursery at Mount Hope, Rochester, New York, c. 1900. [28] The photograph is also captioned 'Belgium Elm', possibly a reference to its source rather than a confusion with the hybrid 'Belgica'. [28] As the nursery later stocked the wych 'Superba', Blandford Elm, it is probable that propagation was from this tree. [20] Arnold Arboretum identified it in 1915 as a varietal form of Ulmus glabraHuds., which would match Blandford Elm, despite the apparent discrepancy in dates. [29]

Putative specimens in the UK

An old example of what appears to be the same clone as the 1880 Kew large-leaved 'Superba' survives (2019) on Leith Links, Edinburgh. The Edinburgh tree has wych samarae and short petioles, with no evidence of hybridization.

Notes

  1. ↑ Possibly Holger Jensen, after whom 'Holgeri' was named.

Herbarium Specimens

  1. ↑ "Herbarium specimen - E00824742". Herbarium Catalogue. Royal Botanic Garden Edinburgh. Sheet described as U. montana var. superba (Kew Gardens specimen, 1880)
  2. ↑ "Herbarium specimen - WAG.1846734". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled Ulmus glabraHuds., formerly called 'Superba'
  3. ↑ "Herbarium specimen - WAG.1846731". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled Ulmus glabraHuds., formerly called 'Superba'
  4. ↑ "Herbarium specimen - WAG.1846732". Botany catalogues. Naturalis Biodiversity Center. Sheet labelled Ulmus glabraHuds., formerly called 'Superba' (with samarae)

Related Research Articles

<i>Ulmus</i> × <i>hollandica</i> Dampieri Elm cultivar

The hybrid elm cultivar Ulmus × hollandica 'Dampieri', one of a number of cultivars arising from the crossing of the Wych Elm U. glabra with a variety of Field Elm U. minor, is believed to have originated in continental Europe. It was marketed in Wetteren, Belgium, in 1851 as 'Orme de Dampier', then in the Low Countries in 1853, and later identified as Ulmus campestris var. nuda subvar. fastigiata DampieriHort., Vilv. by Wesmael (1862).

<i>Ulmus glabra</i> Lutescens Elm cultivar

The Wych Elm cultivar Ulmus glabra 'Lutescens', commonly known as the Golden Wych Elm, arose as a sort of a wych found in the York area in the early 19th century by W. Pontey of Pontey's nursery, Kirkheaton, Huddersfield, who propagated and distributed it. The original tree he named the Gallows Elm for its proximity to a gallows near York. Loudon in The Gardener's Magazine (1839) identified it as a form of Ulmus montana, adding 'Lutescens' by analogy with Corstorphine sycamore, Acer pseudoplatanus 'Lutescens'.

<i>Ulmus</i> Exoniensis Elm cultivar

Ulmus 'Exoniensis', the Exeter elm, was discovered near Exeter, England, in 1826, and propagated by the Ford & Please nursery in that city. Traditionally believed to be a cultivar of the Wych Elm U. glabra, its fastigiate shape when young, upward-curving tracery, small samarae and leaves, late leaf-flush and late leaf-fall, taken with its south-west England provenance, suggest a link with the Cornish Elm, which shares these characteristics.

The elm cultivar Ulmus 'Atropurpurea' [:dark purple] was raised from seed at the Späth nursery in Berlin, Germany, circa 1881, as Ulmus montana atropurpurea, and was marketed there till the 1930s, being later classed as a cultivar by Boom. Henry (1913) included it under Ulmus montana cultivars but noted that it was "very similar to and perhaps identical with" Ulmus purpureaHort. At Kew it was renamed U. glabraHuds. 'Atropurpurea', but Späth used U. montana both for wych elm and for some U. × hollandica hybrids, so his name does not necessarily imply a wych elm cultivar. The Hesse Nursery of Weener, Germany, however, which marketed 'Atropurpurea' in the 1950s, listed it in later years as a form of U. glabraHuds..

<i>Ulmus</i> Purpurea Elm cultivar

The elm cultivar Ulmus 'Purpurea', the purple-leaved elm, was listed and described as Ulmus Stricta Purpurea, the 'Upright Purpled-leaved Elm', by John Frederick Wood, F.H.S., in The Midland Florist and Suburban Horticulturist (1851), as Ulmus purpureaHort. by Wesmael (1863), and as Ulmus campestris var. purpurea, syn. Ulmus purpureaHort. by Petzold and Kirchner in Arboretum Muscaviense (1864). Koch's description followed (1872), the various descriptions appearing to tally. Henry (1913) noted that the Ulmus campestris var. purpureaPetz. & Kirchn. grown at Kew as U. montana var. purpurea was "probably of hybrid origin", Ulmus montana being used at the time both for wych elm cultivars and for some of the U. × hollandica group. His description of Kew's U. montana var. purpurea matches that of the commonly-planted 'Purpurea' of the 20th century. His discussion of it (1913) under U. campestris, however, his name for English Elm, may be the reason why 'Purpurea' is sometimes erroneously called U. procera 'Purpurea' (as in USA and Sweden.

<i>Ulmus</i> × <i>hollandica</i> Serpentina Elm cultivar

The putative hybrid cultivar Ulmus × hollandica 'Serpentina' is an elm of unknown provenance and doubtful status. Henry identified it as intermediate between U. glabra and U. minor, a view accepted by Bean and by Melville, who believed that the specimens at Kew bearing the name 'Serpentina' were U. glabra "introgressed by U. carpinifolia" [: U. minor] and were similar to but "distinct from 'Camperdownii'".

The elm cultivar Ulmus 'Monstrosa' [: "monstrous", "strange"], a shrub-elm with fasciated branching, is believed to have originated in France, where it was first listed by Lavallée in Arboretum Segrezianum (1877) as a form of Field Elm, Ulmus campestris var. monstrosa, but without description. Though its long slender 2 cm petiole is not a feature of wych elm U. glabraHuds., and is even less likely in a shrub form of this species, the wych-cultivar error arose early, perhaps because the Späth nursery of Berlin, using Ulmus montana both for some Ulmus × hollandica cultivars and for wych varieties, listed it c.1890 as Ulmus montana monstrosa. Hartwig in Illustrirtes Gehölzbuch (1892) followed with Ulmus scabra monstrosa, an error repeated by Krüssman (1962) and by Green (1964), with their U. glabraHuds. 'Monstrosa'.

The Wych Elm cultivar Ulmus glabra 'Corylifolia Purpurea' was raised from seed of 'Purpurea' and described as U. campestris corylifolia purpurea by Pynaert in 1879. An U. campestris corylifolia purpurea was distributed by the Späth nursery of Berlin in the late 19th and early 20th centuries. The Hesse Nursery of Weener, Germany, corrected the U. campestris corylifolia purpurea of their 1930s' lists to U. glabraHuds.corylifolia purpurea by the 1950s. Green listed 'Corylifolia Purpurea' as a form of U. glabra.

The putative Wych Elm cultivar Ulmus glabra 'Dovaei', or Doué elm, was raised by the André Leroy nursery at Angers, France, as Ulmus dovaei, before 1868. The Baudriller nursery of Angers marketed it as Ulmus Dowei, "orme de Doué", suggesting a link with the royal nurseries at nearby Doué-la-Fontaine, which stocked elm. Green considered it a form of wych.

The putative Wych Elm cultivar Ulmus glabra 'Latifolia Nigricans' was first described, as Ulmus campestris latifolia nigricans, by Pynaert in 1879. Pynaert, however, did not specify what species he meant by U. campestris. The tree was supplied by the Späth nursery of Berlin in the late 19th century and early 20th as Ulmus montana latifolia nigricans. Späth, like many of his contemporaries, used U. montana both for Wych Elm cultivars and for those of the U. × hollandica group.

<i>Ulmus glabra</i> Macrophylla Elm cultivar

The putative Wych Elm cultivar Ulmus glabra 'Macrophylla' [literally 'long-leaved', though also 'large-leaved'] was first mentioned by Lavallée in 1877 as U. montana var. macrophylla (fastigiata). The Späth nursery of Berlin marketed an U. montana macrophylla in the late 19th and early 20th century; both Späth and the Hesse Nursery of Weener, Germany, supplied it in the 1930s. At that time, Ulmus montana was used both for wych elm cultivars and for hybrid cultivars of the Ulmus × hollandica group.

<i>Ulmus glabra</i> Nana Elm cultivar

The dwarf wych elm cultivar Ulmus glabra 'Nana', a very slow growing shrub that with time forms a small tree, is of unknown origin. It was listed in the Simon-Louis 1869 catalogue as Ulmus montana nana. Henry (1913), referring his readers to an account of the Kew specimen in the journal Woods and Forests, 1884, suggested that it may have originated from a witch's broom. It is usually classified as a form of Ulmus glabra and is known widely as the 'Dwarf Wych Elm'. However, the ancestry of 'Nana' has been disputed in more recent years, Melville considering the specimen once grown at Kew to have been a cultivar of Ulmus × hollandica.

Ulmus × hollandica 'Pitteurs' or 'Pitteursii', one of a number of hybrid cultivars arising from the crossing of the Wych Elm Ulmus glabra with a variety of Field Elm Ulmus minor, was first identified by Morren as l'orme Pitteurs (1848). Elwes and Henry (1913) and Krüssmann (1976) listed it as an Ulmus × hollandica cultivar. It was named after the landowner Henri Bonaventure Trudon de Pitteurs of Saint-Trond, near Liège, Belgium, who discovered and first propagated the tree on his estate.

<i>Ulmus</i> × <i>hollandica</i> Superba Elm cultivar

The hybrid elm cultivar Ulmus × hollandica 'Superba' is one of a number of intermediate forms arising from the crossing of the Wych Elm U. glabra with a variety of Field Elm U. minor. Boulger tentatively (1881) and Green more confidently (1964) equated it with a hybrid elm cultivated in the UK by Masters at Canterbury in the early 19th century, known as "Masters' Canterbury Seedling" or simply the Canterbury Elm. Loudon examined a specimen sent by Masters and considered it a hybrid, calling it U. montana glabra major.

<i>Ulmus glabra</i> Latifolia Elm cultivar

The putative Wych Elm cultivar Ulmus glabra 'Latifolia' was identified in Audibert's Tonelle (1817) as U. campestrisLinn. [ = U. glabraHuds.] latifolia. The tree is reputed to have originated circa 1750 in or around Mechelen, and to have been widely planted throughout Belgium. A 1912 herbarium specimen from Oudenbosch, however, shows a hybrid leaf labelled Ulmus hollandica latifolia.

The elm cultivar Ulmus × hollandica 'Blandford' was listed by the Urban Forestry Administration (UFA) of the District Department of Transportation in Washington, D.C., as one of its 'street trees' in 2008. As the UFA has no further documentation to support it, the entry may be spurious, but it is most likely the tree is the wych elm cultivar Ulmus glabra 'Superba', known in the UK as the 'Blandford Elm' and introduced to the US in the early 20th century, or possibly the hybrid cultivar Ulmus × hollandica 'Superba' present in some American collections, including Garfield Park, Washington, D.C., in the mid-20th century.

<i>Ulmus</i> × <i>hollandica</i> Wentworthii Pendula Elm cultivar

Ulmus × hollandica 'Wentworthii Pendula', commonly known as the Wentworth Elm or Wentworth Weeping Elm, is a cultivar with a distinctive weeping habit that appears to have been introduced to cultivation towards the end of the 19th century. The tree is not mentioned in either Elwes and Henry's or Bean's classic works on British trees. The earliest known references are Dutch and German, the first by de Vos in Handboek tot de praktische kennis der voornaamste boomen (1890). At about the same time, the tree was offered for sale by the Späth nursery of Berlin as Ulmus Wentworthi pendulaHort.. The 'Hort.' in Späth's 1890 catalogue, without his customary label "new", confirms that the tree was by then in nurseries as a horticultural elm. De Vos, writing in 1889, states that the Supplement to Volume 1 includes entries announced since the main volume in 1887, putting the date of introduction between 1887 and 1889.

<i>Ulmus</i> × <i>hollandica</i> Fastigiata Elm cultivar

The hybrid elm cultivar Ulmus × hollandica 'Fastigiata' was first listed and described as Ulmus glabra fastigiata, a narrow-crowned elm with large smooth leaves, by Petzold and Kirchner in Arboretum Muscaviense (1864). C. Berndt of the Berndt Nursery, Zirlau, Schweidnitz, described an elm of the same name in Mitteilungen der Deutschen Dendrologischen Gesellschaft, that he had received in 1903 "from a renowned nursery in Holstein" as Ulmus montana fastigiata macrophylla. A tree of that name had been listed by Dieck in 1885 without description. Berndt reported that his U. glabra fastigiata was "easy to confuse with U. montana superba", a tree "known in the Magdeburg region as Ulmus praestans", a statement confirming that, like that cultivar, his tree was a form of U. × hollandica. Karl Gustav Hartwig who received specimens of U. praestans from Kiessling of the Magdeburg city nursery in 1908, concluded (1912) that U. glabra fastigiataKirchner was indistinguishable in leaf or habit from U. praestans. An U. campestris glabra fastigiataArb. Musc. [ = Kirchner] was distributed by the Hesse Nursery, Weener, Germany, in the 1930s, where it was listed separately from U. praestans.

<i>Ulmus</i> Fastigiata Glabra Elm cultivar

The elm cultivar Ulmus 'Fastigiata Glabra' was distributed by the Späth nursery, Berlin, in the 1890s and early 1900s as U. montana fastigiata glabra. Späth used U. montana both for cultivars of wych elm and for those of some U. × hollandica hybrids like 'Dampieri'. A specimen of U. montana fastigiata glabra in the Royal Botanic Garden Edinburgh was determined by Melville in 1958 as a hybrid of the U. × hollandica group.

<i>Ulmus glabra</i> Concavaefolia Elm cultivar

The Wych Elm cultivar Ulmus glabra 'Concavaefolia', a form with up-curling leaves, was listed in Beissner's Handbuch der Laubholz-Benennung (1903) as Ulmus montana cucullataHort. [:'hooded', the leaf], a synonym of the Ulmus scabraMill. [:glabraHuds.] var. concavaefolia of herbarium specimens. An Ulmus campestris cucullata, of uncertain species, had appeared in Loddiges' 1823 list, but Loudon's brief description (1838) of concave- and hooded-leaved elms was insufficient for later botanists to distinguish them. The earliest unambiguous description appears to be that of Petzold and Kirchner in Arboretum Muscaviense (1864).

References

  1. 1 2 3 "New and splendid ornamental elm - Ulmus montana superba". The Gardeners' Chronicle and Agricultural Gazette: 670. 1845.
  2. ↑ Lindley, J., 'The Elm', The Gardeners' Chronicle and Agricultural Gazette, 13 September 1845, p.628, col.3
  3. 1 2 3 4 Morren, Charles (1848). "Notice sur l'Orme des montagnes". Journal d'Agriculture Pratique de Belgique. 1 (1): 411–414. Retrieved 2017-02-21.
  4. 1 2 Henrard, D. (1845). Morren, Charles (ed.). "Sur un voyage fait en Engleterre et en Écosse". Annales de la Société royale d'agriculture et de botanique de Gand. 1: 155–168. Retrieved 2017-02-22.
  5. 1 2 Katalog (PDF). Vol. 108. Berlin, Germany: L. Späth Baumschulenweg. 1902–1903. pp. 132–133.
  6. ↑ Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. Vol. 7. pp. 1873–1874. Republished 2004 Cambridge University Press, ISBN   9781108069380
  7. 1 2 Späth, Ludwig (1930). Späth-Buch, 1720-1930. Berlin: Self published. pp. 311–313, 351–352.
  8. ↑ Beissner, Ludwig (1912). "Ulmus praestans". Mitteilungen der Deutschen Dendrologischen Gesellschaft. 21: 227.
  9. ↑ Späth catalogue 1911/12, p.137
  10. ↑ Hartwig, Karl Gustav (1913). "Ulmus praestans". Mitteilungen der Deutschen Dendrologischen Gesellschaft. 22: 302.
  11. ↑ Spath, L (1912). "Ulmus praestans = U. montana superba". Möllers Deutsche Gärtner-Zeitung. 27 (15): 177. Retrieved 17 October 2017.
  12. ↑ Loudon, John Claudius (1838). Arboretum et fruticetum Britannicum. Vol. 3. p. 1404.
  13. ↑ Hanham, F. (1857). A Manual for the Park (Royal Victoria Park, Bath). Longman, London.
  14. ↑ Boulger, George Simonds (1881). McLaren, John (ed.). "On British Elms". Transactions of the Royal Scottish Arboricultural Society. Edinburgh. 9: 39. Retrieved 18 October 2017.
  15. ↑ Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 16 February 2017.
  16. ↑ Rehder, Alfred (1915). "Neue order kritische Gehölze". Mitteilungen der Deutschen Dendrologischen Gesellschaft. 24: 215–219. Retrieved 18 October 2017.
  17. ↑ Rehder, Alfred. "Ulmaceae". Bibliography of cultivated trees and shrubs hardy in the cooler temperate regions of the Northern Hemisphere. Jamaica Plain, Massachusetts: The Arnold Arboretum of Harvard University. pp. 135–143. Retrieved 18 October 2017.
  18. 1 2 Bobbink and Atkins, Rutherford. N.J. Rutherford, N.J. : Bobbink & Atkins. 1902. p. 51.
  19. ↑ Hovey & Co., Boston, Mass., Catalogue of ornamental trees & shrubs, evergreens and climbing plants, 1855, p.5
  20. 1 2 Ellwanger & Barry, Descriptive Catalogue of Hardy Ornamental Trees ... at the Mount Hope Nurseries (Rochester, N.Y., 1868), p.9
  21. ↑ Ellwanger & Barry, Descriptive Catalogue of Hardy Ornamental Trees ... at the Mount Hope Nurseries (Rochester, N.Y., 1875)
  22. ↑ Ellwanger & Barry, Descriptive catalogue of hardy ornamental trees, shrubs, etc. (Rochester, NY, 1880), p.39
  23. ↑ Bobbink and Atkins, Rutherford. N.J. Rutherford, N.J. : Bobbink & Atkins. 1909. p. 51.
  24. ↑ General catalogue, 1904 : choice hardy trees, shrubs, evergreens, roses, herbaceous plants, fruits, etc. New York: Frederick W. Kelsey. 1904. p. 18.
  25. ↑ "Urban Forestry Administration". District Department of Transportation. Archived from the original on 16 July 2010. Retrieved 20 June 2016.
  26. ↑ Saunders, William; Macoun, William Tyrrell (1899). Catalogue of the trees and shrubs in the arboretum and botanic gardens at the central experimental farm (2 ed.). Ottawa. pp. 74–75.
  27. ↑ "ePIC - Detailed results from Living collection for ulmus". epic.kew.org. Retrieved 2017-10-19.
  28. 1 2 Meeham, Joseph (1903). "Ulmus Campestris Superba". The Florists' Exchange. 15: 230.
  29. ↑ "European Elms" (PDF). Bulletin of Popular Information. Arnold Arboretum, Harvard University. 1 (14): 56. 23 July 1915. Retrieved 18 October 2016.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.