Have you ever considered how difficult it would be to communicate were it not for names? Assigning names to things is important, since they are part of human communication and represent a "shorthand" method of identification. Indeed, it would be hard to imagine what our lives would be like without names for things like people, places, animals, and plants.
The act or process of naming something is known as nomenclature. Yet, names can lead to confusion because, in many cases, there is a good deal of overlap. For example, the use of common or regional names to identify plants can be misleading, depending upon the plant in question. First, the same common name might refer to different plants in various regions of the world. For example, the common name "blue bell" refers to a plant in the genus Campanula in Scotland, Endymion in England, Hyacinthus in France, and Eustoma (and others) in the United States.
In contrast, the same plant might be called a different common name in various regions of the world or, at times, within a relatively small geographic area. To further illustrate this point, the common weed broad-leaf plantain has 45 English names, 75 Dutch names and 106 German names. In response to this confusion, the scientific naming system was developed.
Until the middle part of the 18th century, the scientific system of plant nomenclature simply involved using Latin words (mostly adjectives) to describe the plant in great detail. For example, the flower carnation had the unbelievably complex scientific name of Dianthus floribus solitariis squamis calycinis subovatis brevissimus corollis crenatis. Obviously, individuals trying to identify plants by using their scientific names were at quite a disadvantage in those days.
In 1736, a Swedish physician and botanist by the name of Carl von Linne changed all of that when he proposed the binomial system of plant nomenclature in his book Systema Naturae. In essence, he proposed that plants (and other living organisms) should receive two Latin names, one representing the genus of the organism and the second its specific epithet. Together these two names scientifically identified a species, and this system of nomenclature is still in use today. Using the binomial system, carnation went from the very cumbersome name mentioned above to become identified simply as Dianthus caryophyllus. Interestingly, in 1761 von Linne "Latinized" his own name to Carolus Linneas, and still is widely regarded as the "father of modern plant taxonomy."
In the scientific naming of plants, the genus is loosely defined as a closely related and definable group of plants comprising one or more species. In the case of some genera (e.g. Ginko) there may be only one species; in the case of others (e.g. Rosa) there may be hundreds. Genera of plants often are named in honor of a person. For example, the genus Begonia, which contains more than a hundred species, is named in honor of Michel Begon (1638-1710) who was governor of Santo Domingo and a great supporter of botanical studies. At other times the genus name simply describes in Greek or Latin terms certain attributes of its members. Campanula comes from the Latin word for bell and is the name given to the genus to which the various species of bell flowers belong.
The second part of a scientific name is its specific epithet. Specific epithets usually are adjectives used to describe the species in Latin terms (e.g., purpurea meaning purple, procumbens meaning prostrate, or odoratus meaning fragrant). One of the more interesting specific epithets is that for the garden flower commonly known as larkspur. It has the scientific name of Consolida ambigua. Literally interpreted, the specific epithet means "not sure" or "uncertain." Evidently, plant taxonomists are not too proud to admit when they're stumped.
In nature, plant species often are subject to specific environmental conditions resulting in a variant form of the species that can reproduce itself without human intervention. The result is known as a "botanical variety." For example, Gleditsia triacanthos is the scientific name for honey locust, a common woodland tree that bears thorns in great profusion. Somewhere in antiquity, a thornless mutation appeared. This variant represents a botanical variety. The Latin word for thornless is inermis which, literally interpreted, means "unarmed." Therefore, the complete scientific name for the botanical variety is Gleditsia triacanthos var. inermis, or thornless honey locust.
With horticultural and other cultivated plants, it is common practice for humans to produce their own variants through genetic manipulation or cultural techniques. These man-made variants are known as "cultivars," which is short for cultivated varieties. For example, selections made from thornless honey locust have produced improved forms of this botanical variety. The cultivar 'sunburst' is a good example. In addition to being thornless, it has new growth which emerges golden yellow and ultimately changes to bright green by mid-summer. The scientific name of this "man-made" variant would be Gleditsia triacanthos var. inermis 'Sunburst', or sunburst thornless honey locust. Please note that, unlike botanical varieties, cultivar names are not italicized but are set off in single tick marks. Cultivars often are sterile and must be vegetatively propagated. At other times they are hybrids whose genetic makeup must be reconstituted each generation by crossing two specific parents.
So, the next time you shop for plants look at the scientific name on the care tag. It is included not to impress you with a scholarly Latin name. Rather, it allows you to be certain that the plant you are about to select is actually the one you wanted to buy. Familiarity with scientific nomenclature will not only make you a wiser consumer, but it will also make you a better gardener as well.