Putative 'Tortuosa', Edinburgh
The elm cultivar Ulmus 'Tortuosa', the Wiggly Elm, was described by Host (1827) as Ulmus tortuosa, and distinguished by Henry from Loddiges' and Loudon's U. tortuosa, which he identified with Ulmus 'Modiolina', "l'orme tortillard" of France. Henry noted, however, that abnormal sinuous or zigzagging growth "might occur in any kind of elm", and herbarium specimens of elms labelled 'Tortuosa' range from U. minor cultivars to U. glabra (see External links below); while a hybrid var. tortuosa cultivar from Louveigné, Belgium, with twisted trunk and large leaves, was described by Aigret in 1905.
The best-known 'serpentining' elm cultivar is Camperdown Elm.
No authoritatively identified specimens are known to survive, though a number of trees matching the description of 'Tortuosa' are found in Edinburgh (2017). Many elm cultivars were imported from Europe by the Royal Botanic Garden Edinburgh in the late 19th and early 20th centuries and distributed about the city.
U. × hollandica forms
Charles Hovey, referring to a tree (possibly 'Tortuosa') in the grounds of Messrs. Hovey & Co., Boston, wrote in 1876: "An elm forming one of a long row, near our daily walk, is a never-failing source of pleasure the year round. It is what I might justly call the zig-zag, or, perhaps, serpent elm. The outline of the head, which is 60 feet (18 m) high, appears quite symmetrical; but the branches which form it run in every possible direction, like huge boa constrictors curled beneath the leaves. Yet these limbs contort and twist in a regular order of their own, and only in winter, except by close examination show their peculiar character." Hovey procured trees from England, Scotland and France in 1844.
An elm of this sort stands in Trinity, Edinburgh, beside South Trinity Rd, in a position that suggests deliberate planting.[note 1] A slow-growing tree (girth 1.3 m, height c.15 m), its ascending trunk zigzigs over twenty times; its branches, some pendulous, also zigzag. The largish leaves, on slender shoots, have short petioles. The tree suckers lightly: a second identical but smaller tree stands nearby. The leaves, light suckering and samarae confirm hybrid origin, and suggest that the tree may be identical to the U. × hollandica 'Modiolina' grown at Kew and the 'Modiolina' introduced to USA. Like the latter, which "produces few seeds, and in some years none at all", the Edinburgh tree is also sparsely flowering, and like l'orme tortillard it has frequent 'bosses' on trunk and branches, which sprout epicormic shoots.
U. minor forms
Two sinuous or zigzagging dwarf-elms (5 m tall) of the U. minor group stand in Calton Hill Park, Edinburgh's oldest public park, above the old Royal High School. U. minor is not native to Scotland, so these trees appear to be cultivars of the 'Tortuosa' type.
- The presence nearby of old U. pumila 'Pendula' above the same former railway cutting confirms that rare cultivars were planted in this location.
- Host, Nicolaus Thomas (1827). Flora Austriaca. 1. p. 330.
- Nicholson, George (1888). The illustrated dictionary of gardening. 8. p. 120.
- Elwes, Henry John; Henry, Augustine (1913). The Trees of Great Britain & Ireland. 7. pp. 1894–1895.
- "Famille XV – Ulmacées". Annales des travaux publics de Belgique. 62: 1226. 1905.
- Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. Arnold Arboretum, Harvard University. 24 (6–8): 41–80. Retrieved 16 February 2017.
- Hovey, Charles Mason (1876). "Arboretum americanum". The Gardener's monthly and horticulturist. 18: 194.
- Google Maps: South Trinity Rd - Google Maps, accessdate: August 15, 2016
- Browne, Daniel Jay (1851). The Trees of America. New York: Harper & Brothers. p. 481.
- "Herbarium specimen - WAG.1852995". Botany catalogues. Naturalis Biodiversity Center. Sheet described as U. tortuosa Host (1833)
- "Herbarium specimen - WAG.1852991". Botany catalogues. Naturalis Biodiversity Center. Sheet described as U. glabra Huds. var. tortuosa
- "Herbarium specimen - WAG.1852993". Botany catalogues. Naturalis Biodiversity Center. Sheet described as U. glabra Huds. var. tortuosa, also known as U. procera modiolina
- "Herbarium specimen - WAG.1852990". Botany catalogues. Naturalis Biodiversity Center. Sheet described as U. glabra Huds. var. tortuosa
- "Herbarium specimen - WAG.1852992". Botany catalogues. Naturalis Biodiversity Center. Sheet described as U. glabra Huds. var. tortuosa