Under the botanical nomenclature of the International Code of Nomenclature for Cultivated Plants (ICNCP), a cultivar group is any gathering of cultivars designated by common traits. Designated groups may include a group of yellow-flowering cultivars, a group of cultivars with variegated leaves, a group of cultivars resistant to a particular disease, etc. A cultivar may belong to more than one group (for example, it may be yellow-flowering, with variegated leaves and resistant to the disease at one and the same time).
- ICNCP Art 9 Ex 10: "Solanum tuberosum 'Desiree' may be designated part of a Maincrop Group and a Redskin Group since both such designations may be practical to buyers of potatoes ..."
Another reason for designating a group is when a well-known plant loses its taxonomic status (e.g. it ceases to be a "good" species or subspecies and becomes a synonym). Its botanical epithet may become a "Group epithet". For example:
- Tetradium hupehense is sometimes regarded as being part of
- Tetradium daniellii and the plants in question may be referred to as
- Tetradium daniellii Hupehense Group.
