What is a "Group" as pertains to Cymbidiums

[Cym Ladye]

I know genus, subgenus and variety as pertain to Cymbidiums. But does anyone know what the meaning of "group" is and particularly why it was used by the RHS for the following from the Registrar's Notes in the RHS Registration List for April - June 2010:

Establishment of new Groups
Cymbidium Asian Tower grex Sinnwanokaori Group. Originated and named by Chihara Takami. Made 13 Apr 2005; f.fl. 10 Mar
2009. Derived from Cymbidium Sarah Jean ‘Ice Cascade’ x Cym. sinense.
Description: Flowers of seedlings range from tepals with soft brown pink to pale mushroom with darker stripes. Lip white to brown
with darker dots or blotches that merge. Flower spikes 30–45 cm, flowers 4–5 cm wide.


Cym Ladye

[Andrew]

It's a horticultural taxonomic rank. A group/cultivar group refers to cultivars that share common trait (as defined by the registered group description). In other plants, groups don't have to be related unless defined in their description. I don't know if the RHS necessitates that groups are contained within a single grex but I haven't come across any orchid groups that aren't. For orchids, the general purpose is to define an individual cross, especially when the choice of parentage results in seedlings that aren't typical of the grex. Unfortunately, while you can register cultivars and groups with the RHS, their grex database doesn't contain listings for them. However, if you comb through the old Sanders lists, you should be able to find other examples of groups that have been registered (cultivars and groups are usually published at the end of the grex list).

[Cym Ladye]

Thank you Andrew. I can understand the use of this registration for more intergeneric classifications but for Cymbidiums, it seems more than a bit cumbersome for lack of another word, especially in reference to a common species to a complex hybrid with another species in the background.

Is this then just the choice of the registrant of the hybrid because the RHS allows it? There are numerous registrations similar to the breeding of the one in question, but none are listed as a "Group". Sounds like the lumpers and the splitters are at work, or are we retreating to the registration formulas of 75 years ago?

CL

[Andrew]

I think it is largely the registrants who are choosing to register groups to distinguish their breeding lines simply because they can. I don't really understand the point of registering a group in the way you described because I doubt anybody is going to refer to the progeny of that cross by the group name.
Personally, I think 'group' a very useful rank that isn't being used properly by breeders and orchid growers. We essentially refer to cultivar groups when we refer to colour forms in orchids. Albas, semi-albas, etc generally have no botanical taxonomic merit as they usually aren't monophyletic. However, horticulturalists still want to use these names and registering them as cultivar groups provides validity to using them in horticultural circles without having to worry what the botanists think.