Ulmus Glabra 'Camperdownii'
The Camperdown Elm Ulmus glabra 'Camperdownii' is a cultivar which cannot reproduce from seed. Although still classed as a cultivar of U. glabra, the tree was considered a nothomorph of U. × hollandica var. vegeta by Green (1964), not U. glabra.
Read more about Ulmus Glabra 'Camperdownii': Description, Pests and Diseases, Cultivation, Notable Trees, Synonymy