Ulmus × hollandica 'Serpentina'

Ulmus × hollandica cultivar
Tree labelled Ulmus hollandica 'Serpentina', Denmark, 1965
Hybrid parentage	U. glabra × U. minor
Cultivar	'Serpentina'

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'".

Koch had listed an U. serpentina in 1872, and an U. montana serpentina was marketed in the 19th century by the Späth nursery in Berlin and by the Ulrich nursery in Warsaw. In Späth catalogues between 1902 and 1920, however, though 'Serpentina' appears, 'Camperdownii' is absent; by 1930 'Camperdownii' appears but 'Serpentina' is absent. This suggests that 'Serpentina' may have been a continental name for 'Camperdownii', and that Späth dropped the name 'Serpentina' c.1930 in favour of 'Camperdownii'. Elwes and Henry's failure to mention the serpentining branches of 'Camperdownii' may have contributed to the impression of two different trees. In this omission they were followed by Bean (1925), Green (1964), Hillier (1972– 2002),Krüssmann (1976), and White (2003), the first four of whom, like Elwes and Henry, list 'Serpentina' as a cultivar distinct from 'Camperdownii'.

The ultimate form of 'Camperdownii' depends on such factors as latitude and location, on what part of the parent tree the cuttings come from, on the 'stock' on which it is grafted, and on possible continuing mutation. Specimens may therefore vary in form, which might account for Henry and Melville's "hybrid" 'Serpentina'.

Henry, quoting Koch, said that 'Serpentina' was sold in nurseries as the Parasol Elm, which was distinguished from Ulmus campestris pendula by having larger leaves. Both 'Serpentina' and the Scampston Elm were sometimes referred to as U. americana pendula. (Other European elms described as 'American' by various nurseries include 'Vegeta','Lutescens', and 'Nana'.)