Orchid Nomenclature

To be able to understand the names you see in an orchid catalogue and to be able to correctly write the name tags of your orchids, you need a basic understanding of orchid nomenclature, the system of naming orchids.

The International Code of Botanical Nomenclature (ICBN) defines a hierarchical structure into which all plants can be classified. Other organisms such as animals have their own equivalent naming system, but there are moves to amalgamate these codes so that all organisms can be named under a single code in the future. 

In addition, the International Code of Nomenclature of Cultivated Plants defines the naming structure for cultivated plants. This code is currently operated by the RHS and results in the Sanders list of orchid hybrids.

The levels of this hierarchy applicable to species orchids are:-

The ranks in bold are recognised by the ICBN as the major ranks. Not all ranks need be used to classify an organism. Only the ranks necessary are used, the bigger the grouping, the more ranks are used.

For naming orchid species, the ranks of Genus and Species must be used plus Variety when applicable. The ranks of subspecies, subvariety, form and subform are rarely used in naming orchids.

Next, some definitions which may make things a bit easier.

Species

Note that for the cultivar name, the varietal epithet is optional. ie. it may or may not exist. Thus, the cultivar name may have three or four terms.

eg. Cattleya skinneri ‘Mistral’ is a valid cultivar name.

Also note that an orchid does not require a varietal or cultivar epithet if these do not apply. ie. Dendrobium speciosum is a valid name for an orchid which is not a named cultivar and is not a variety of the species.

Natural Interspecific Hybrids

Naturally occurring hybrids within a genus are often given a name.

Dendrobium x delicatum is a natural hybrid between Dendrobium kingianum and Dendrobium speciosum.

Note that the x is often omitted in practice, but should be included to be technically correct. The x should be lowercase.

Natural Intergeneric Hybrids

Naturally occurring hybrids between two different genus are often given a name.

Note that the x is often omitted in practice, but should be included to be technically correct. The x should be lowercase.

Author Citations

In some publications, particularly scientific publications, the names of orchid species or natural hybrids will be suffixed with the the author who originally described the orchid. Due to the large number of taxonomic changes occurring with orchids and the same name being used by different authors for different orchids, the addition of the author ensures that the orchid to which the name refers is non-ambiguous.

Author names are generally abbreviated. Abbreviations have not been standardised in the past, but the ICBN recommends the use of Brummitt & Powell's Authors of plant names (1992). These standard abbreviations can be found at the IPNI, Author Query page.

In addition to the standard author abbreviations, you may also see other terms.  The most commonly encountered terms are:-

The examples below will help with the correct usage of author citations.

Artificial Hybrids

A hybrid-generic name is created from the crossing of plants from two different genus and the hybrid-generic name is normally composed of a combination of the names of both genus.

eg. a Laeliocattleya is a hybrid of a Laelia and Cattleya

eg. a Potinara is a hybrid of Cattleya, Brassavola, Laelia and Sophronitis.

Note that there is no varietal epithet possible in a hybrids name.  Only species can have a varietal epithet.

Listed Parents

Orchids will often be written as a crossing of the parent plants. This is normally due to the hybrid not being a registered hybrid (a new hybrid is registered by completing the required forms and paying the required fees) or so the parent plants are individually listed. This is often done by nurseries when the parents are awarded plants thus making the children more likely to be high quality and thus making the seedlings more desirable.

Note that the female parent is always listed first when a hybrid name is written as the cross of the parents. Normally, when the genus of both parents is the same, the second occurrence of the genus is omitted. eg. Paph. bellatulum X delenatii

Abbreviations

Although abbreviations for the generic name or hybrid-generic name are not part of the ICBN, the generic name or hybrid-generic name of orchids are often abbreviated in common use. Scientific literature will always use the ICBN naming system however, and use the full generic name or hybrid-generic name and never an abbreviation.

There are lists of ‘standard’ abbreviations for the genus and hybrid-genus in the orchid hybrid register of over 700 abbreviations. Most of the more common abbreviations are quickly memorised, although only the keenest grower could learn all 700.

Unfortunately, not all groups publishing these abbreviation lists agree on the abbreviations to be used, and, as these abbreviations do not form part of the ICBN, no body formally owns these abbreviations and can dictate the correct abbreviation to be used. Generally, however, most abbreviations will be the same in all lists. There are a few exceptions however, notably Dendrobium which have the abbreviations of Den and D in common use.

For a list of abbreviations, refer to my links page.

Thus, some completed valid names would be:-

D. nobile var. sanderanum ‘Emily Hale’

Cym. Girl Crazy

C. mossiae var. wageneri

Awards

Orchids which are of exceptional quality, are unusual or exhibit outstanding features may be granted awards to signify their quality. To get an orchid awarded, the orchid normally must be of exceptional quality and grown to perfection.

There are many different award systems throughout the world, but the awards used in Australia by the AOC (Australian Orchid Council) are:-

    Awards are appended to the end of the orchid name. The name of the awarding society should also be appended to the award.

Ploidy

Ploidy, although strictly not part of an orchid name, is often seen appended to the end of orchid names in orchid catalogues. Ploidy is the number of sets of chromosomes for the orchid. A normal orchid has two sets of chromosomes (2N), one set from each parent. Some orchids have more than the normal two sets, with three, four or even more sets of chromosomes.

Generally, orchid with more than two sets of chromosomes are more vigorous growers with larger more desirable flowers, hence a much more desirable orchid.

When the ploidy is specified in the orchid name, the chromosome set count is appended to the orchid name.

Sanders

Now that you know all about orchid names and how to correctly write them, all that’s left to know about is Sanders. Sander & Sons Orchids of St Albans, England, started a system for the registration of orchid hybrids and published the first issue of Sanders in 1906. This became the international authoritative list of orchid hybrids and was taken over by the Royal horticultural Society in 1960 due to the workload involved. The RHS has continued to publish Sanders periodically ever since. There are now 8 volumes of Sanders containing all hybrids registered from 1854 to 1995 with the next volume due shortly. There is also now a CD version for use on your computer which includes all volumes plus numerous photos of awarded orchids from around the world.

Each Sanders volume contains:-

Due to the large numbers of grex, only those grex registered in the year range of the volume, eg. 1991-1995, are included together with the parentage of the grex with their crosses. Unfortunately, this means that to find a grex of interest, you may have to search several volumes to locate its entry.

Thus, the function of Sanders is to provide an authoritative list of hybrid genera. Thus, Sanders is the book to use if you wish to research the parentage of a hybrid or you wish to locate the grex name of a cross in your collection, or even if you just wish to check the spelling of your orchids name. (Surprisingly, about 10% of orchid names in the monthly plant competition are incorrect due to incorrect abbreviations, bad spelling, superseded names or failure to use the named grex instead of the parents.)

Sanders is available from the society library during meetings for research, but is a reference book and thus not available for loan. Sanders is the bible for orchid hybrids, so all members should be familiar with this valuable reference.

Graham Corbin