The hybrid elm cultivarUlmus × hollandica 'Dauvessei', one of a number of cultivars arising from the crossing of the Wych ElmU. glabra with a variety of Field ElmU. minor, is a very rare cultivar said to have originated at the D. Dauvesse nursery in Orléans, France before 1877.[1][2]
Description
According to Henry's description (1913) based on a tree at Kew, the branches ascend to form a broad, pyramidal crown; the leaves bear a resemblance to Wych Elm, but are generally smaller, rarely exceeding 10 cm long by 5 cm wide, and thinner in texture, with petioles nearly 1 cm long.[3][4][5]Krüssmann added that the leaf-base was more oblique.[2]
The US National Arboretum, however, described the 'Dauvessei' that once grew in West Potomac Park, Washington, D.C., as similar in appearance to English Elm (in its lower latitude growth-form), forking at about 2 metres, reaching about 20 m tall by 18 m broad.[6] Herbarium specimens from the Washington trees show less elongated, rounder leaves than those at Kew, with fewer vein-pairs.[7]
There are no confirmed surviving specimens of 'Dauvessei'. A tree obtained from Lee of Hammersmith in 1879 grew at Kew Gardens, where it attained a height of 40 feet (12 m).[3] In the United States specimens stood along The Mall in Washington D.C. among American Elms on either side of the Reflecting Pool (2009),[8][9] but it is not known whether any survive. A 2018 Cornell University study of the National Mall elms found five possible Ulmus × hollandica there (cultivar unidentified).[10] A tree acquired from the Nobelius nursery in 1929 and grown at the University of Adelaide Waite Arboretum, Australia, died in 1997; Melville confirmed the 'Dauvessei' identification, reconfirmed by the arboretum in 1992.[11]
Putative specimen
In the UK a broad pyramidal tree matching 'Dauvessei' descriptions[3][2] and 'Dauvessei' herbarium material from a specimen in West Potomac Park, Washington, D.C., producing hybrid-type samarae, stands in the east corner of Claremont Park, Leith, by Seafield Place. Its location and tidy shape suggest a named cultivar.[12][13][14]
^Went, J. A. (1954). The Dutch elm disease - Summary of 15 years' hybridisation and selection work (1937–1952). European Journal of Plant Pathology, Vol 60, 2, March 1954.