A note on the Nomenclature of Wisteria

As with many commercially available cultivars of plants, Wisteria has had reclassification in recent years.

Since Peter Valder’s book Wisteria – A Comprehensive Guide, published in 1995, which has generally been accepted as the definitive nomenclature guide for the last thirty odd years, much research has been done into the nomenclature of Wisteria, including DNA research both here in the UK and in Belgium, and some changes were made in the new RHS monograph by James Compton and Chris Lane, Wisteria – A Complete Guide, published in 2019.

All the names I have used in the collection are under this new nomenclature, and this is a brief explanation as to the changes.

Changes to the Japanese species of Wisteria

W. x valderi ‘Murasaki-Kapitan’ was originally included in the species W. brachybotrys as W. brachybotrys ‘Murasaki-Kapitan’ but is now recognized as a hybrid. It twines clockwise instead of anticlockwise as in all the other brachybotrys cultivars.

W. x valderi ‘Eranthema’ was originally named W. floribunda ‘Eranthema’, and is also recognized as a hybrid.

Similarly, the ‘Burford’, ‘Hocker Edge’ and ‘Lavender Lace’ hybrids are now classified as x Valderi cultivars.

All the above have been named in recognition of Peter Valder’s work.

With the species W. floribunda, whites, pinks, doubles and the very long racemed varieties have been reclassified as forms of floribunda, so are now known as W. floribunda forma alba, W. floribunda forma rosea, W. floribunda forma pleniflora and W. floribunda forma multijuga respectively.

Changes to the North American species of Wisteria

Previously, there were two recognized species, W. frutescens and W. macrostachya, but as a result of recent DNA studies, the modern classification is one species only, W. frutescens, with macrostachya as a variation within that species.
So, a plant which was W. macrostachya ‘Aunt Dee’ is now known as W. frutescens var. macrostachya ‘Aunt Dee’.