Registration of Group or Grex Names
Dr. A.C. Leslie
International Rhododendron Registrar
The International Registration Authority is now prepared to consider for registration collective names for assemblages of hybrid Rhododendrons. This may involve either a group or a grex name and although both are acceptable under the International Code of Nomenclature for Cultivated Plants, the former is to be preferred.
Such epithets should be coined with great restraint and only where their use is considered essential by the breeder. Moreover, in no circumstances should a selected clone of a group be given the same name (e.g. Rainbow group and cv Rainbow). However, the use of that group name as an element in a cultivar name is permitted (e.g. Rainbow group and 'Blue Rainbow').
It is not necessary for every new collection of hybrid seedlings to be given a collective name.