One of the most frustrating aspects for new gardeners is the use of scientific or botanical plant names. Believe it or not, botanical names were created by Carolus Linnaeus to make plant names easier. Before Linnaeus created the binomial (bi = two and nom = name) system in the 1700s, each plant had several names.
Why Latin? | Why are Scientific Names Used? | How Plant Names are Structured | How to Write a Plant Name | More Information
Why Latin?
Scientific names are Latin or Latinized versions of words. Latin was chosen because it is a "dead" language, meaning word meanings remain unchanged over time. This is important since many Latin names describe an attribute of the plant and it would be difficult if the meaning changed. This stability, combined with many 18th-century European scientists already being familiar with Latin, made it an ideal choice for a universal naming system. Linnaeus, who developed this system, was so fond of Latin that he Latinized his own name to Carolus Linnaeus, from Carl Von Linne.
Why Do We Prefer Scientific Names?
The best reason for not using common names when referring to plants is that they are often more confusing than the botanical name.
The Same Plant Can Have More Than One Common Name
Common names can vary by location and are in the speaker's native language. This means that the same plant may have more than one common name. For example, the linden tree (Tilia) is also known as basswood, lime tree, and bee tree.
One Common Name Can Refer to More than One Plant
There are also several common names that are used for more than one species of plant. The common name, lime tree, can be used to describe the citrus fruit tree (Citrus limetta) or the shade tree (Tilia cordata) - two very different plants.
Scientific Name Elminates Confusion
With all this variation in common names, using a universal binomial naming system eliminates any confusion. The scientific name applies to only one species and is used in all parts of the world regardless of the language spoken.
In some cases we get lucky and the widely used common name is also the scientific name of the plant. This is true for plants like Hosta, Viburnum, Forsythia, Ginkgo, or Begonia.
In other cases, common names may have once matched the genus name but are then changed. Scientific names not only provide a universal name, but they also indicate how plants are related to each other. However, after being named, occasionally, a plant is studied more carefully and botanists learn that they are actually not as closely related as once thought and must be renamed to more accurately show their relation to other plants. In some of these cases the scientific name changes, but the common name (once aligned with the scientific name) does not. For example, sansevieria is now classified as Dracaena and the asters native to North America are now known as Symphyotrichum.
How Plant Names are Structured
Species Name
The scientific names of plants are comprised of the genus and the specific epithet. Together, the genus and specific epithet make up a species name for a plant.
This binomial naming system is similar to an individual's name. Our last name identifies us to a particular group (family) like Darwin, Lincoln, or Kusama. The Genera (plural for Genus) of Acer, Quercus, and Salvia do the same for plants. Our first name identifies us specifically, such as Charles, Abraham, or Yoyoi. The specific epithets rubrum, alba, or splendens do the same. Put these two words together, and you have the name of a specific individual (Charles Darwin, Abraham Lincoln, or Yayoi Kusama) or a specific plant species (Acer rubrum, Quercus alba, or Salvia splendens).
Hybrids
Some garden plants are the result of the crossing of two different species. For example, silver maple (Acer saccharinum) can be crossed with red maple (Acer rubrum) to get a hybrid. These hybrids are often given a new specific epithet name and a multiplication symbol proceeds it to indicate that it is a hybrid (Acer saccharinum × rubrum = Acer × freemanii, the Freeman maple).
Cultivars and Varieties
Many garden plants are further identified with a variety or cultivar name. Varieties often occur in nature and most are true to type. That means the seedlings grown from a variety will have the same unique characteristics as the parent plant.
Cultivar means "cultivated variety" and is a plant that is selected and cultivated by humans. Cultivars can result from sports or mutations, hybrids, and other types of selective breeding and are not necessarily true to type. Cultivars are often named for people or places, typically in the native language of the breeder. Cultivar names can describe the most significant trait of the plant and are often selected to be memorable or marketable.
Learn more in this article: What is the difference between a cultivar and a variety?
Patented & Trademarked Names
Cultivars are sometimes patented or trademarked to protect the breeders' rights. This provides legal protection around the name. Patents can be granted for up to twenty years and give the breeder exclusive rights to propagate and sell that particular cultivar allowing them the opportunity to make money from their plant selection.
Trademarks are used to prevent the name from being used for any other similar plant. This keeps others from marketing or selling the plant using that name and allows the breeder to make more revenue from their plant selection. These names are identified by the use of trademark (™) or registered trademark (®) designations.
Trademarked names cannot be the same as the cultivar name. A cultivar name is considered descriptive of the plant. A trademark name is considered a "brand name." If the trademark name is used as the cultivar name, the name becomes generic and loses its trademark status. For this reason, a trademarked plant will have two names: its trademark name (often memorable, catchy, or descriptive) and its cultivar name (often nonsensical, making it rarely used in commerce). For example, a narrow-growing ginkgo cultivar is trademarked as Princeton Sentry®, but its cultivar name is 'PNI 2720.' Occasionally trademarked names are written erroneously as the cultivar name (for example, Ginkgo biloba 'Princeton Sentry'). This is an incorrect way to refer to a trademarked plant.
Authority
In scientific papers, the scientific name for a species will also include a name or abbreviation after the specific epithet that refers to the person who named the plant. Some prolific botanists will have an abbreviation. For example, in the name Acer rubrum L., the "L" stands for Linnaeus, and in Acer miyabei Maxim., the "Maxim." stands for Karl Maximovich. For other scientific names, the authority may simply be their entire name, without an abbreviation (for example, Acer × freemanii A.E. Murray).
Gardeners rarely have a need to know the authority and so frequently, this information is not included in references and resources intended for gardeners.
How to Write a Plant Name
Scientific names have some standards to follow when writing them.
Species Names
The genus name is always capitalized and the specific epithet is lowercase. The binomial name is italicized (or underlined when handwritten) (e.g., Panicum virgatum). When the specific epithet is not known or not needed, the genus name is followed by "sp." or "spp." which is not italicized. (e.g., Hosta sp.)
If you are referring to several species in the same genus, the genus name can be shortened to just an initial followed by a period for subsequent species names after the full genus name was written once (e.g., Rosa arkansana, R. blanda, and R. carolina).
The authority, if indicated, is after the binomial name and is not italicized or underlined.
Hybrids
Intergeneric hybrids (those between two species in the same genus) are indicated with a multiplication symbol (×) between the two specific epithets or before the hybrid name (e.g., Quercus alba × robur; Quercus × bimundorum).
The multiplication symbol is often substituted with a lowercase "x" for ease, even though the multiplication symbol is more appropriate.
Varieties & Cultivars
Variety names are also italicized, lowercase, and are preceded by "var." (e.g., Gleditsia triacanthos var. inermis)
Cultivar names come after the full scientific name (genus, specific epithet, and variety). They are surrounded by single quotes, not italicized, and may or may not be capitalized. Alternatively, cultivars can be written without the single quotes and preceded by "cv." (e.g., Syringa vulgaris 'Sensation'; Salvia officinalis cv. Tricolor; Gleditsia triacanthos var. inermis 'Sunburst')
Trademarked Names
Trademarked names are not part of the scientific name and, therefore, should not be written as such. They are typically written with the common name or after the scientific name and always with the proper designation (™ or ®).
Common Names
When writing a common name in English, there are a few things to remember. Common names, in general, are written in lowercase (e.g., marigold, red oak). If the common name includes a proper noun, that word should be capitalized (e.g., English oak, Allegany spurge).
When the common name is the same as the genus name, it is typically lowercase when used as a common name (e.g., iris, hosta).
All of this said, we often see capitalized common names, especially when we write them on signage or in lists. We do this for the same reason we capitalize "Mustard" on the sign advertising a sale in the grocery store or "Milk" and "Ketchup" when we put them on our grocery list - it looks better or is easier to read. So, cut someone some slack if they capitalize a common name, they are almost always capitalized on the garden center signs!
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