Compilers' standpoint

International guidelines
The nomenclature used in the Lists of names complies with the international guidelines, as stated in the "International Code of Botanical Nomenclature" (ICBN; 2000, the so-called Saint Louis Code) and the "International Code of Nomenclature for Cultivated Plants" (ICNCP or Cultivated Plant Code; 2004). Especially the latter publication is very important to this edition of the Lists of names, because it gives guidelines for the nomenclature of cultivated plants, and it was revised shortly before the new Lists were published. The ICNCP (2004) gives new guidelines for the definition and nomenclature of cultivars and cultivar groups (called “groups” in the new ICNCP), which are followed as much as possible in this List of names. Cultivar denominations are now only considered to be correct in their original language, the number of words in a cultivar denomination is no longer limited to three, the number of syllables is no longer limited to 10 and there are some words that may no longer be used in cultivar names (e.g. “variety”, “seedling” and “selection”). On a large number of subjects the code has become much less restrictive. In the new ICNCP the term cultivar group (or group) has received a much wider definition, stimulating more frequent use. Cultivar groups can now be used for classifying cultivars (of Rosa, Rhododendron, Phlox and Paeonia for example), but they can also be used to indicate individual plants. That is why some cultivar groups can be found alphabetised like names within the Lists. There has also been a change in the spelling of Japanese cultivar names. A macron (overscore) above a vocal is used to indicate it should be pronounced long, for example the ō in ‘Shōjō-nomura’. The ICNCP advises to use the Hepburn system to convert Japanese characters into the Roman alphabet.

New taxonomical interpretations
Our knowledge of the world’s flora is still incomplete. New data and a better understanding, for example gained through DNA research, inevitably have consequences for the classification and nomenclature. Usually, new interpretations are marked improvements on the old ones, and are accepted without much resistance by scientists and nurserymen alike. But it regularly occurs that two or more different interpretations are equally accepted. This means that sound choices have to be made in determining preferred names, based, if possible, on the opinion of experts. The Lists of names indicate names that were not chosen as synonyms, placed between brackets. The names that were not chosen as preferred names, in this case are not “wrong” or “invalid”, strictly speaking. In this edition, besides corrections of spelling mistakes and interchanges of names also many taxonomical changes have been carried through. The major criteria for acceptance of changes are that they must be derived from a reliable source, and that the new name is already used elsewhere, for example by the International Cultivar Registration Authorities (ICRA). Some changes were already announced in the previous edition (e.g. Thuja orientalis ® Platycladus orientalis; Pernettya ® Gaultheria). Furthermore in the genera Clematis and Rosa many names have changed, based on the new publications “Clematis Register & Checklist” and “Modern Roses XI”. The chapter “Name changes of well-known plants”, elsewhere in this edition, lists the most important changes. The complete list of name changes can be found on the internet (www.internationalplantnames.com).

Plant breeders’  rights and trademarks - a short introduction
Plant breeders’ rights imply that a certain cultivar is the legal property of the owner of the rights. Without his permission in certain countries and regions this protected cultivar may not be commercially grown. Trademarks do not protect a plant but protect a name. The trademark may not be used without permission of the owner in certain countries or regions. These types of protection must be registered with legally recognised Plant breeders’ rights agencies or trademarks agencies. A plant protected by Plant breeders’ rights must be given a scientifically correct cultivar name. This cultivar name must always be used to indicate the plant, and everyone may freely use it. It is not allowed to use a trademark as the cultivar name of a plant. Only the cultivar name guarantees the identity of the plant and is inseparably connected to one cultivar only. This name can always and in all countries be used to indicate this specific plant. Trademarks and other trade names are not part of the scientific name of plants, but can be given to plants for commercial reasons. One cultivar can have several trade names and one trade name may be used for several cultivars. When using trademarks and trade names the cultivar name of the plant should always be mentioned as well. This can be done in different ways (see chapter “User’s guide”)

Plant breeders’ rights and trademarks in the Lists of names

Contrary to previous editions now information is given on protection by Plant breeders’ rights and trademarks in Europe. This is an express wish of the ENA and of many users. The difficulty in providing this information is, that it gets outdated quickly and especially checking trademarks is difficult in practice. Also, protection is not valid everywhere, but only in certain countries or regions. There is also the danger of legal claims by owners of Plant breeders’ rights and trademarks. Advised by ENA, the “European Plant Names Working Group” has chosen not to search actively for information, but to let the owners of the rights send it themselves. Potentially interested owners have been approached by letter. Also press releases have been sent to national and international specialist publications. The symbols for Plant breeders’ rights and trademarks included in this list have been given based on the information provided by the owners. The owners themselves are responsible for this information. A random sample of the received information has been verified. The correctness of this information is not guaranteed and it is certainly not complete.  It should always be checked with the official Plant breeders’ rights agencies and trademarks agencies! (See chapter: Main registration agencies of Plant Breeders’ Rights and Trademarks, elsewhere in this edition).

On the Internet page (www.internationalplantnames.com) links can be found to the web sites of the official registration agencies. They can provide information on whether the protection is currently valid and for which countries and regions the protection applies. Sometimes the name or protection status provided by the owners has not been accepted by the editors. For example if the request was to indicate a cultivar name as a protected trademark. Also trade names for which the owner did not indicate the cultivar or cultivars it is used for, were not accepted. Both for Plant breeders’ rights and trademarks in Europe there are no legally recognised symbols to indicate the protected status. For this List symbols have been chosen that are commonly used: ^PBR for Plant breeders’ rights and ® for trademarks. For certain plants it was impossible to determine whether the only known name was the cultivar name or a trade name. In those cases the name has been listed as a cultivar name. To differentiate between trade names and cultivar names, according to the guidelines of the ICNCP, the trade names have been printed in a different font. At the request of the commercial users trade names and trademarks have been printed in a more prominent font in this edition. Sometimes cultivar names, even years after the introduction of the cultivar, are registered as trademarks, and sometimes the plants are even given a new cultivar name. This type of nomenclature is not allowed by the ICNCP and has been ignored in the Lists of names. Owners of Plant breeders’ rights or trademarks who want to have their protected plant or name included in the Lists, can enter them on the website (www.internationalplantnames.com). These new registrations will be checked and added to the website, and will also be incorporated in the next printed edition of the Lists of names.

 The editors of the Lists of names are not responsible for incorrect indications of protection by Plant breeders’ rights or trademarks, nor of lacks of indications. Neither are they responsible for the possibly incorrect orthography of the cultivar names and trademarks involved.

Important reference works
For the classification of genera into families there are various views and the nomenclature used is not uniform. This edition of the Lists of names follows Brummitt (1992): “Vascular Plant Families and Genera”. This is a change from the previous edition, which followed Cronquist (1988): "An integrated system of classification of flowering plants". All family names are derived from the name of the type genus of the family, for example not Compositae but Asteraceae, named after type genus Aster. The International Cultivar Registration Authorities have an internationally accepted status as registrars of existing and new cultivar names.  Their lists, addresses and other information can be found on www.ishs.org/icra/index.htm. After the previous edition of the Lists was published several new important publications and Internet sites have appeared, which have been incorporated now. This was the case with new publications on Rosa, Taxus, Buxus, Clematis, Prunus, Hydrangea, Lavandula, Agapanthus and Anemone. Important recent general reference works are: “The Plantfinder 2005-2006” and “Handwörterbuch der Pflanzennamen” by Zander (2002). An updated literature list of major reference works can be found in the back of this edition.