'Pitteurs Pendula' was listed by C. de Vos in Handboek Supplement 16, 1890, as Ulmus pitteursii pendula. However, Hans M. Heybroek, erstwhile head of the elm breeding programme at the de Dorschkamp Research Institute for Forestry and Landscape Planning at Wageningen, Netherlands, identified the tree as Zelkova × verschaffeltii.[1]
References
edit- ^ Green, Peter Shaw (1964). "Registration of cultivar names in Ulmus". Arnoldia. 24 (6–8). Arnold Arboretum, Harvard University: 41–80. Retrieved 16 February 2017.