A cultivar is a particular type of cultivated plant that people have created or selected for its interesting features. Tradescantia Hub was appointed International Cultivar Registration Authority (ICRA) for the Tradescantia genus in 2022 (here is the official page on the ISHS website, the organisation which appoints ICRAs), and that was expanded to the entire Commelinaceae family in 2025. That means I’m officially in charge of keeping track of all cultivar names that are ever used in the family, throughout the world.
As ICRA, I follow a detailed set of rules that have been internationally agreed for decades. The official version is very long and wordy, but I’ve also written a plain english translation.
There are three elements to the job of ICRA:
1. Documenting old names for existing cultivars
Cultivars are often distributed with multiple different names, and it can be hard to know which is correct. My job is to make an official decision about which name is right for each cultivar, and publish it to make it definitive. This will stabilise names within the family from history and into the future, so that everyone will be able to use the right name for any plant.
I finished my initial research for the Tradescantia genus, but my work on the rest of the family has only just started. All the information I’ve compiled so far is publicly, freely available to everyone in the online checklist. So hopefully in future no-one else will ever have to repeat the detective work I did on old names!
To find out about the details of my process, you can read my research paper about the work. You can also check out some articles about particular cultivars or interesting questions I’m working on on.
2. Registering new names for new cultivars
Anyone can make up a name for a new plant and start selling it. But the ICRA system exists to make the process more organised and systematic, so that it’s easier for everyone to benefit from. When someone creates a new Commelinaceae cultivar, they can register it directly with me, and I will:
- Make sure the name follows the rules.
- Publish the name so that it becomes established and official, and no-one can override it later.
- Keep a permanent archive of information about the plant and its origins, so that anyone in the future can find out about it.
This entire process is free and has nothing to do with money, trademarks, or patents. The information is freely publicly available for anyone to benefit from. And people creating new cultivars get help to publish and document them. Everybody wins!
If you have a new cultivar you’d like to register, you can get started here.
3. Cultivar checklist
The two parts above come together to make a cultivar checklist, which should contain every known cultivar name from the entire family – old and new.
Having a unified checklist makes it easy to check and compare names that might have been duplicated or reused. Each valid cultivar is connected to any synonyms that have been used for it, so that it’s easy to correct mislabelled plants. It also includes all the information that’s available about the history and origins of the plant, as well an explanation for any decisions where I had to choose between multiple established names for the same cultivar.
You can view the checklist here, and read a guide on how to use it. The Tradescantia genus is complete, but the rest of the family is still a work in progress.
You can also read the detailed report on my entire research process to find out more about how it all works.
