1d. Carpinus betulus ‘ Heterophylla’ C. betulus var. heterophylla G.Kirchn., Arboretum Muscaviense: 667 (Petzold & Kirchner 1864). – C. betulus f. heterophylla (G.Kirchn.) K.Koch, Dendrologie 2 (2): 3 (Koch 1873). – Original citation: No detailed data given. – Type: not localized. – Note: Kirchner gave the name “ heterophylla ” to plants that have both normal-shaped leaves and deeply serrated leaves, regardless whether the leaf serration is of the ‘Incisa’ or ‘Quercifolia’ type, which he regarded as synonymous, as did Koch. As the mutation occurs spontaneously and may be fixed by cuttings, this name ‘Heterophylla’ is complicated to use. Kirchner refers to “Bth. cat.”, meaning the catalogue of James Booth and Söhne nursery in Klein-Flottbek, Hamburg, Germany. As there is no reference to Loudon, Kirchner’s name cannot be regarded as a clear recombination of C. betulus var. heterophylla hort. ex Loudon, which is an invalid name published as a synonym of C. betulus ‘Quercifolia’. Therefore, Kirchner’s name is not illegitimate, but rather a later homonym.

Published as part of Holstein, Norbert & Weigend, Maximilian, 2017, No taxon left behind? - a critical taxonomic checklist of Carpinus and Ostrya (Coryloideae, Betulaceae), pp. 1-52 in European Journal of Taxonomy 375 on page 8, DOI: 10.5852/ejt.2017.375, http://zenodo.org/record/3838542