Rules for naming cultivated plants
2. Cultivar names should be as short as practical
Cultivar epithets should not contain excessively long words that may be difficult to write or pronounce. On or after 1 January 1996 they must consist of no more than 30 characters (Roman letters, numbers and permitted punctuation marks and symbols), excluding spaces and the demarcating single quotation marks.
3. Cultivar names can be made-up words
Cultivar epithets do not have to consist of existing words but may be novel inventions. They can take the form of code of up to 10 letters excluding spaces. However, they must not consist only of a single letter or only of numerals.
4. Cultivar names should not make exaggerated claims
After 1 January 1959 cultivar epithets must not include superlatives relating to the merits of the cultivar (e.g. ‘Earliest of All’); these could become confusing through later introduction of cultivars of similar (or better) qualities.
5. Some words are banned from cultivar names
After 1 January 1959 cultivar epithets may not contain the words “form” or “variety” or their abbreviations or equivalents in other languages. After 1 January 1996 cultivar epithets may not contain the following words: “cultivar”, “grex”, “group”, “hybrid”, “maintenance”, “mixture”, “selection”, “sport”, “series” and “strain” or the plural of these words, or the words “improved” and “transformed”, or their equivalents in any language.
6. Symbols and some punctuation are banned from cultivar names
After 1 January 1996 only the apostrophe (‘), comma (,), up to two non-adjacent exclamation marks (!), the full stop (.), the hyphen (-), forward slash (/) or backward slash (\) can be included in cultivar names.
7. Words in cultivar names should be spelled in full
Cultivar epithets or parts of them should not be abbreviated with the exception of words or forms of address normally abbreviated by linguistic custom (e.g. Mr in place of Mister). The use of such abbreviations is optional and if desired the abbreviated word may be spelled in full, the two variants being treated as equivalent epithets. If an epithet is established using initials of personal names these may not subsequently be spelled out in full.
8. Cultivar names should not be the same as the genus name
After 1 January 1996 cultivar epithets must not contain the Latin or common name of the genus to which the cultivar is assigned.
9. Within a genus cultivar names should not duplicate pre-existing names
Only in exceptional circumstances should cultivar epithets be re-used within a genus (or denomination class, or group of similar genera), nor should they be so similar to any existing epithet as to be likely to cause confusion. Nevertheless it is now permissible under the Cultivated Plant Code to re-use a cultivar epithet if this is unlikely to cause confusion and if the epithet has only rarely been used in publications. In addition the International Cultivar Registration Authority should be satisfied that the original cultivar:
In the world of seed-testing and seed marketing legislation, cultivar epithets may be re-used if the original cultivar has not been in commercial existence for several years, even though it may still exist in genebanks or germplasm collections. To avoid confusion between cultivars with the same epithet, especially in databases, citation of a breeder’s reference, application number or year of first registration is strongly recommended.
10. Group names follow similar rules to cultivar names
Epithets at the rank of Group are formed according to similar rules as cultivars. However, they should never be placed within single quotation marks and should always contain the word “Group” as the first or last word of the epithet (or its equivalent in other modern languages). Epithets for grex names, used in orchid nomenclature are formed in a similar way although there are several exceptions to their presentation. See the ICNCP for details.