Orchids are named under the same international system that governs the naming of all other plants. But orchids aren’t exactly like other plants. The orchid family is incredibly large and orchid species interbreed so easily that it is often difficult to tell where one species stops and the next begins. It is the taxonomists’ challenge to organize the myriad forms and colors of orchids into neat and discrete categories.

The complexity of these categories is reflected in the fine distinctions made among apparently similar plants and hybrids that have elaborate family trees. However, the basic principles are those followed in the naming of any plant. Few people can rattle off the various rules and exceptions of orchid naming, but for any grower, even a general notion of the system will contribute to the enjoyment to be derived from this remarkably diverse family of plants.

How Orchids Are Named.

To understand how an orchid gets its name, it is best to start at the top, with the orchid family (Orchidaceae). For most plants, the next major category used below family is the genus. Because the orchid family is so large, botanists use intermediate categories between the family and genus called tribe and subtribe, categories that can be helpful because they show how the plants in the different genera are related.

The genus Miltonia, for example, is in the subtribe Oncidiinae. This subtribe also includes the genera Oncidium, Odontoglossum, and Brassia, all of which have similar characteristics and hybridize easily.

Again for most plants, a genus is divided into species, the basic units of classification in both the plant and animal kingdoms. The genus Miltonia, for example, contains the species spectabilis. An easy way to remember how genus and species names are related is to look at the first few letters of both words. Genus is general; species is specific. The plants in a given species are all quite similar, but you will still find differences in flower size, shape, and color, as well as in the leaves, stems, and pseudo bulbs.

Sometimes certain plants in a species share a characteristic that makes them different from others in the species, but not quite different enough to justify a new species name. If such a group is found in nature, it is called a variety. Variety names are often preceded by the abbreviation var. Miltonia spectabilis var. moreliana, for example, has rose rather than white flower petals, but aside from this difference in color, it is virtually identical to the white-petaled forms of Miltonia spectabilis.

Variety names are used primarily by botanists, who study populations of wild plants. In a horticulture-the study of cultivated plants-the term “cultivar” is used more frequently. Cultivars are plants selected for their desirable features and propagated in ways that perpetuate those features. A cultivar may be selected from a species, hybrid, or a variety. It may be propagated by division, offshoots, mericloning, or by any other asexual method that produces offspring similar to the parent plant. Cultivar names are printed in roman letters. The first letter is capitalized, and the entire name is enclosed in single quotes. For example, it turns out that one of the prettiest forms of Miltonia spectabilis var. moreliana has been widely cultivated and awarded. This clone, named ‘Royalty’, is a cultivar of a variety. It takes its place at the bottom of the family tree.

Orchids With More Than One Name.
Unfortunately, everyone doesn’t always use the same names for orchids. Over the years, taxonomists have tried and discarded several schemes for organizing orchids along evolutionary lines. The goal-a classification system that shows how plants are related-is worthwhile but becomes difficult to attain when many names must be changed to reflect a new botanical discovery.
To return to the family tree, the name of the cross between Miltonia spectabilis and Miltonia clowesii is Miltonia Bluntii (you can tell from the word’s Latin ending that this is an old hybrid, named before the rules prohibited Latinized hybrid names). Miltonia Bluntii is a primary hybrid-also known as an interspecific grex-produced when one species is crossed with another species. Primary hybrids are not as common as more complex hybrids, which are produced when a hybrid is crossed with a species or another hybrid. Now that the value of species orchids is becoming widely recognized.
Common Names.
Common orchid names are as confusing and misleading as the common names of other plants. Although easier to pronounce, the words rarely point directly to a specific plant and are thus of little value. A single common name often applies to several species-species that have nothing else in common. For example, there seems to be at least one spider orchid on every continent, and new ones are probably dubbed every day. Better simply to call them all orchids, a very general but at least correct name. At any rate, most orchid species don’t have common names. The genus name is often used informally as the common name.