Classification of orchids

Hybrid Cymbidium orchids
Hybrid Cymbidium Orchids

There are certain rules that apply when naming any type of plant, including orchid plants. Most plants are named using just a genus name and a species name as per the International Code of Botanical Nomenclature (ICBN), but in the case of orchids, there are more rules that have to be heeded since there can be so many hybrids of one particular orchid plant. Each and every orchid hybrid requires a hybrid name. This then results in orchids also being subject to the International Code of Nomenclature for Cultivated Plants (ICNCP).

When one describes an orchid plant, the species or genus name is followed by a unique name. This name is usually derived and given by the describing botanist. Botanical classification is done in a hierarchical fashion. This means that each higher rank, such as an order or family includes a number of subordinate groups that most probably share certain characteristics. In general orchid classification is a means whereby one can understand the many species better and put them into context. For example there is an artificial classification that divides orchids into groups and can help a cultivator to identify unfamiliar plants as well as provide clues on how to care and grow certain plants. Artificial classifications include group nomenclature such as terrestrial, epiphyte, cool- or warm growing, etc.

Climate conditions

All orchids are classified as per their preferred climatic conditions in which the can grow and thrive. There are basically three different types of climatic conditions that are used to classify orchids. They are the cool-climate orchids, the intermediate climate orchids and the warm climate orchids.

The cool climate orchids

Temperate climates, cool-growing orchids, at high elevations to facilitate the cooling of the orchid by cloud cover – Cool-climate orchids grow naturally in areas from as far afield as China until Northern Australia. The orchid plant that comes to mind immediately is the Cymbidium orchids. Cymbidium orchids make up the largest of the potted orchid selections that can be found.

In the Andes the orchids are cooled by moist clouds in the late afternoon. The examples here include Odontoglossum and Masdevallia orchids. It has been found that Odontoglossum orchids hybridize easily with the Oncidium orchid which is a warmer-growing orchid.

In South Africa, especially on Table Mountain and in Madagascar the Disa orchid grows in the cool winds all year round with cold rain and occasional snow falls in winter. They experience high summer temperatures, but mountain streams keep the orchid plant roots cool and make the weather conditions tolerable.

The following examples are naturally cool-climate orchids: Cymbidium orchids, the Odontoglossum Alliance and the different types of Odontoglossum orchids, the Disa uniflora and its hybrids, the Pleione orchid, the Zygopetalum orchid and the Dendrobium orchid, the Masdevallia, Brassia and of course the Coelogyne orchids.

There are also Terrestrial orchids that also resort under the cool-climate orchids. They are the Cypripedium orchid, Oriental Cymbidium orchids, the Diuris and Pterostylis orchids, the so-called Jewel Orchid (Goodyera and Ludisia), and the Epipactus and Spiranthes orchids.

The intermediate climate orchids

The orchids classified as intermediate-climate orchids grow naturally in climates that are neither too hot nor too cold. They occur naturally between temperate and tropical zones. The optimum environment for these orchids has a temperature that is subtropical. In this group most of the orchids prefer bright, but not direct sunlight and will be most comfortable in a semi-shaded area. A covered patio is thus ideal. (Tip: create this environment using 40-50% shade cloth.)

Of the most notable examples of intermediate climate orchids are the: Oncidium orchids and their intergeneric hybrids, the warm-tolerant Cymbidium orchids, the ever-popular Miltonia orchid and the Miltoniopsis orchid, the different lady slipper orchids or as they are also known, the Paphiopedilum orchids. Amongst the Paphiopedilum orchids, the Maudiae, the Cochlopetalum, the Multiflorals, the Brachypetalums, the green-leaf species and the Parsvisepalum orchids are the hybrids. Then there are also the Lycaste and Anguloa orchids. And last but not least, the Bulbophyllum and Cirrhopetalum orchids also form part of the intermediate climate orchids.

The warm climate orchids

These orchids occur naturally in the tropical areas. Warm climate orchids require warm, humid conditions and only slightly cooler winter temperatures. The most significant factor in these orchids' cultivation is the humidity that is required. Tropical areas such as East, Central and South America boast many beautiful orchids that occur there naturally. They include the Phalaenopsis (or the moth orchid as is it more popularly known as) and the lady slipper orchid i.e. the Paphiopedilum orchid. Cattleya orchids, the Cattleya alliance and its intergeneric hybrid orchid partners; and Phragmipedium orchids are also increasing in popularity amongst orchid collectors and cultivators. The Phragmipedium orchids come in various types. These types are the shorter-petalled group, the long-petalled group, and miniature green-flowered and of course the Phragmipedium schlimii.

And we also need to mention the Catasetum orchid, the Vanda orchid and the many varieties and hybrids of Vandaceous orchids, the Ascocenda, Angraecum and Aerangis orchids as well as the Calanthe orchid also reside under this group of orchids.

Cultivars and Hybrids

Orchids are very complex flowers due to the many different characteristics that have been developed by orchid cultivators. This has a very complex nomenclature consequence. Interpreting orchid named is thus quite important if you have ambitions of becoming a serious orchid collector or cultivator or even an orchid grower. Within an orchid species, any one orchid plant may exhibit features that make it unique within that species. It can be either in size of color. These differences within a species are known as varieties or forms and are usually denoted as follows:

Dendrobium nobile pendulum where the genus name is Dendrobium, the species name describes the orchid flower as nobile and the variety is given as pendulum meaning free swinging.

The word Cultivar is a combination of cultivated and variety and means that the plant has been vegetatively propagated through dividing or cloning, rather than from seed to produce a genetically unique orchid plant. Within a cultivar all the offspring are genetically identical. All cultivar names are controlled and regulated by the ICNCP. When a cultivar is named, the customary Botanical name is used and the cultivar name is added to it. For example Phalaenopsis equestris 'Candor Violette', FCC/AOS (The FCC/AOS indicates the fact that the plant has been awarded a First Class Certificate by the American Orchid Society.)

A Hybrid on the other hand is a cross between genetically different orchid plants. Orchid hybrids are identified by a grex. Orchid hybrids, when produced from seed and regardless of variations or form or color share a common lineage and thus are classified as members of the same grex. This in essence means hybrids that have the same parentage. Cultivars may be given individual names, but the grex name will precede them when classified. For example Phalaenopsis HiLo Lip 'Candor Violette', where the grex name is HiLo Lip.

For classification purposes and to understand the names of orchids around the world it is best to remember the following points:

  • The genus name is started with a capital letter. It can also be abbreviated as in Dendrobium amethystoglossum or Den. Amethystoglossum.
  • Species and variety names are always in lower case.
  • Genus, species, and variety names are always in italics.
  • Variety or form is written as 'var.' or 'forma' in Roman typeface.
  • Grex names are written in Roman typeface with initial capitalization.
  • Cultivar names are also written in Roman typeface, with initial capitalization, and enclosed in single quotation marks.
  • Awards are abbreviated and appear in capital letters.