What is a cultivar?
The cultivar is a special category of plants.
The word was first used by Liberty Hyde Bailey in 1923 to refer to plants from cultivation that are selected, invented, or maintained by humans for desirable characteristics. The term, and then in 1953 an entire separate code called the International Code for Cultivated Plants, arose from a need to refer to these selected plants; especially in contrast to the scientific rank of variety (var.).
The rank of variety, is based on differences that occur below the species level in nature and usually across a geographic range. The variety generally represents speciation in action. The cultivar represents the selected plants we grow for particular characteristics.
One does not disclude the other. From a variety or species from nature, interesting characteristics may arise and a cultivar may be stabilized and selected. Cultivars can also be selected from hybrids created in cultivation. For practical purposes, a separate system of nomenclature was created in order to give names to cultivars. This is called The International Code of Nomenclature for Cultivated Plants (ICNCP). Publishing “fancy” non-latin epithets following their scientific classification under the ICN/Madrid Code makes it easy for us to communicate about these plants without confusion.
Below is the formal definition from Article 2.3 of the ICNCP. See All of Article 2 beginning on page 6 for further details:
“A cultivar, as a taxon, is an assemblage of plants that (a) has been selected for a particular character or combination of characters, and (b) remains distinct, uniform, and stable in those characters when propagated by appropriate means.”
Here is a closer look at what this means, broken down by the key terms. These can mostly be found precisely defined by the authors of the International Code of Nomenclature for Cultivated Plants (Brickell et al., 2016)
Taxon– A unit, defined on the basis of shared characteristics. In this case, the cultivar. (p. 177, Brickell et al.)
Assemblage– More than one; a group. A cultivar is not one plant, but an assemblage that has been propagated from one original, or was discovered as an assemblage and chosen from nature. (Article 2.3 Brickell et al. 2016)
Selected– Chosen or isolated from anywhere such as a nursery, from among a batch of seeds or growing up a tree.
Character(s) or a combination of characters-Observable features of any kind. For some examples: shape or color of the leaves, thickness of vine, color or structure of inflorescence, growth habit. Any quality or trait that “may serve to distinguish one taxon from another” (p. 142 Brickell et al. 2016).
Remains distinct– The cultivar is unique. Its (combination of) characters should distinguish it from any other similar cultivars as it is grown and propagated through successive generations. “Consistently different so as to allow repeated recognition” (p.145 Brickell et al. 2016).
Uniform-These distinguishing characteristics “do not vary beyond a defined limit” (p. 160 Brickell et al. 2016) ..for which they have been selected.
Stable- The characters of the new cultivar are predictable over time, as succeeding generations are propagated (Article 2.3 &2.12 Brickell et al.2016)
Appropriate methods of propagation– Any method that results in identical offspring containing the selected characteristics. For Hoya the most common methods of propagation are cloning by stem cuttings and, more recently, tissue culture. Whatever the method, the results are what matters: if you have an identical offspring, it may be included in the cultivar. If the characters of offspring have changed, it may not be included in the cultivar.
Naming Your Cultivar
When you select your own new cultivar, you may name it yourself by publishing it. Cultivar names are established when they are printed in dated material with a distinguishing description and it is circulated. This can be a book, journal, nursery catalog, or registration with the International Cultivar Registration Authority (ICRA) for the relevant genus who will then review and publish the name for you.
To register your new Hoya cultivar with the ICRA, you can fill out one of the forms embedded below in the format of your choosing, or send the responses by email.
A separate article will cover more of the in’s and out’s of coming up with a unique, acceptable cultivar name, but in the meantime, some basic guidelines:
A new cultivar name begins with the genus name: Hoya
The fancy part in single quotes is written with each new word capitalized and is called the ‘Cultivar Epithet’
The species or lower classification is optionally included where it is known and provides further information without confusion.
Example:
Hoya lacunosa ‘Royal Flush’
– New cultivar epithets must be at least partly in any modern language.
– They may not be solely in latin.
-They must be unique to Hoya (they should not have been used before for another taxon).
– These words and equivalent words are banned in new cultivar epithets in all languages: hybrid, cultivar, grex, group, form, maintenance, selection, sport, strain, series, variety, improved, transformed.
-Ask for permission before naming a new cultivar for a living person.
– They should not exaggerate the attributes of the cultivar through superlatives or make it sound like it cannot be improved, for example ‘Best Ever’.
-For complete guidelines, see the ICNCP. For abbreviated guidelines, see page 131 of the ICNCP. To submit a name and have it reviewed, see below.
Note: The ICRA does not grant legal rights to originators such as patents or PVR which must be sought through local protections dependent upon country. The ICRA is charged with registering and establishing the names of all cultivars within a genus and following the most recent guidelines of the International Code of Nomenclature for Cultivated Plants. Cultivars may be independently published or separately patented or granted PVR rights and then submitted to the ICRA for registration so that the name is maintained in the ICRA Checklist with reference to where it was published.