There are serious problems in canna nomenclature which would seem to be intractable. A long time ago I realised that I can do no more than sharing my database containing details of over 3.000 varieties, to assist in responsible naming. This seems to have largely been ignored.
Species Nomenclature
The first frustrating problem is that of species nomenclature. Historically there have been some 200 species described in International botanical literature. Within the past few years taxonomists have radically reduced the number of valid species names to around 24. Unfortunately, some invalid species names are deeply ingrained in the horticultural literature. Even the RHS Plant Finder disregards current taxonomic opinion.
Cultivar Nomenclature
The more intractable problem is the nomenclature of horticultural cultivars. The foundations of cultivar nomenclature was laid down by the International Botanical Union many years ago. There are essentially two aspects to the problems with cultivar naming.
Cowboy Naming
Firstly, a set of rules published as the “International Rules of Nomenclature for Cultivated Plants”, now in its 9th edition, states in its basic rules:
1. Each plant variety shall have only one name.
2. The only valid name is the original name.
In the world of professionally organised plants, such as orchids and roses, responsible breeders follow these rules. Unfortunately there is no organisation of any sort in the Canna world, and these basic rules have been almost totally ignored. The names of plant varieties have been often changed, commonly as a marketing exercise. We often see the re-launch of an old, established variety as a “new” variety by the horticultural trade, and some of the biggest names are the worst offenders.
My canna database shows that at least a quarter of canna names are just synonyms, and in some cases they are synonyms of synonyms!
Cultivar Registration
The second aspect is the setting up of “Official Registrars” to compile and maintain a register of variety names. A registrar was appointed for each plant genus. The registrar for cannas is the KAVB in Holland (The Royal Dutch Bulb Growers Association). The KAVB published an index of canna variety names in 1990. This was a momentous work, and described some 300 varieties at that time known in literature.
Unfortunately, canna breeders (with a few notable exceptions) have ignored the requirement of responsible breeders to register new varieties, even though there are no costs involved. The problem is that the International Rules are not backed by law, so there is no incentive to comply with them.