Welcome to the home of the International Cultivar Registration Authority (also called an ICRA) for the genus Hoya, and an online learning resource dedicated to the genus in cultivation.
An ICRA is an individual or organization appointed by the International Society for Horticultural Science (ISHS) that is charged with registering and establishing the names of cultivars for a particular plant group. This aims to promote stability in the names of cultivated plants and preserve their history. The most simple reason to name and publish plants is so that we can understand them and discuss them without confusion.
Register Hoya cultivar and Group Names: You can learn more about what this means and then apply to register a cultivar or Group name right here.
A cultivar may originally be selected for one or more unique features from nature or a nursery. It may be a hybrid or open pollinated. The expanded definitions are found in Chapter II,Article 2 of the International Code of Nomenclature for Cultivated Plants. If you are not sure if your selection qualifies as a unique cultivar, Submit a registration form or send me a message, and let’s find out.
If you have a brand new mutation or hybrid which has not made its features known yet, keep on growing it. It may qualify to be a cultivar eventually, but it’s important to have enough of your cultivar to introduce to a market, and have time to compare it against others in the trade. A cultivar by definition is an assemblage of plants, and not an interesting occurrence in a personal collection. Cultivars are meant to be introduced to the trade.
Guide to using the Cultivar Checklist:
Each name entry is assigned to one or more of the categories below. A name may be a synonym and established, because it was published after the name which is accepted and established, or it may be invalid because it breaks an important rule in the International Code of Nomenclature for Cultivated Plants.
Accepted: The name is accepted as the correct name representing a unique cultivar. It may still need to be formally established in the next print registry. In more simple words, it is the name to use.
Synonym: An established name that is not the accepted or adopted name. (ICNCP 11.2-11.3)
Invalid:A name contrary to the rules of the code, or which was never established, and/or does not represent a unique cultivar.
Established: A name attached to a unique cultivar, which has been published meeting all conditions of Article 27.
Established Undetermined:A name which has been established meeting all conditions of Article 27, but which may or may not be attached to a still extant cultivar, or to one which is unique.
There is always only one accepted name for any cultivar, even though in some cases multiple may have been established. Many cultigens* (cultivated plants which may or may not have cultivar status, or are of unknown origin) are not necessarily established.
Using the Checklist:
You can sort by the categories or by tags, or use the search function. Simply select which category you would like the list to be ordered by. The entire list will be published in print and distributed annually, and each individual cultivar registration is available in a file in the offices of the Registrar.
Is the list complete? Are all accepted cultivars here right now?
This is an ongoing checklist. While checklists are always incomplete by their very nature, the ICRA was established in July of 2023 and the checklist itself was launched in January of 2024. There are many names which still need to be added at every status. Over time the objective is to maintain a checklist which also contains market names and trade designations as they come up, as well as the accepted and invalid names of cultivars. Would you or someone you know like to work with the ICRA?
If you have any problems ordering the list, finding a particular cultivar, or have notice any potential errors, please reach out. There are many new and old names which are being added rapidly and currently still as of 7/4/2024. When the list is as updated as possible, that status will be updated.
Please contact me at any time regarding potential errors, to register a cultivar, and with any questions or concerns.
About the ICRA & Registrar
I am Rachel Colette Conroy, an independent researcher in Michigan, USA. I keep a large collection of Hoya here to study, share, and preserve, as well as a library of publications, research material, and herbaria. All are available to the public by appointment, and will be added to this the site or stemmajournal.org digitally where copyright permits.
While the ICRA is technically an individual structure, there is a collective of people and organizations who have been collaborating with me to make these ventures what they are and what they will become. It especially would not be possible without the very tangible support, opportunity, and priceless materials provided from those who have assisted and partnered with the ICRA in big ways at late and early hours. A committee list and more appropriate ‘thank you’ is forthcoming.
In addition to the ICRA, I also have the privilege of working with Mark Randal on his project, Stemma Journal, a publication dedicated to the genus Hoya for every enthusiast. From the time I first got seriously into growing, I have admired Randal’s ability to transform complex topics about cultivation and taxonomy into something beautiful to look at and fun to read. Many of these same people collaborating with through the ICRA are a part of a special network with Stemma Journal. If you aren’t a part of the Facebook Group over at Facebook.com/groups/stemmajournal , I hope I might encourage you to check it out for some very cool conversations, and early access to the journal volumes that are hosted on stemmajournal.org .
It is through collaboration with Stemma Journal that new cultivars which have just been registered, or are about to be registered, will be primarily distributed in both print and pdf. We hope that more new originators* will want to share and describe their cultivars through this process, or publish them directly, so that Hoya cultivar names will be clearly established and easily searchable in a way that they have not been in the past.
Wherever you are in the wider world, welcome to the registry and an online world of Hoya cultivars. If you are here to register a cultivar and learn how to establish its name so that it has nomenclatural priority, you are in the right place. This is also the single place to check the correct name for a cultivar within the genus, and its status.
Definitions:
Cultivar- A cultivar as a taxon is an assemblage of plants (more than one) which has been selected for one or more unique features from nature or a nursery. The cultivar may be a hybrid or open pollinated. The expanded definitions are found in Chapter II,Article 2 of the International Code of Nomenclature for Cultivated Plants. (If you are not sure if your selection qualifies as a unique cultivar, Submit a registration form or send me a message, and let’s find out). In order to formally become a cultivar, it must be published with its new name and a thorough description that differentiates it from others. (Registration turns this into a step by step process).
Cultigen- An assemblage of plants which is known only in cultivation and exists primarily due to human activity, but which has not necessarily been formally named and published under the Cultivated Plant Code.
Originator- someone who ‘selects’, or even creates, a cultivar.