Binomial Nomenclature: What is it and why is it important?

From before the time of Christ when Latin was the literary language in Europe, botanists have attempted to both classify and name plants in a way that both organizes the plants and describes the nature of the plant.

It wasn’t until the mid-1700’s that a Swedish botanist by the name of Carl Linnaeus simplified and developed a universal system of naming botanicals. Linnaeus’ 1753 Species Plantarum gave every plant a two word Latin name and hierarchical classification system based on observable plant characteristics. This two word Latin name is known today as binomial nomenclature (binomial – means two names, nomenclature – is the system used for naming things).

Importance of Binomial Nomenclature

Before Linnaeus came along and simplified things, plants usually had many long descriptive Latin names, making learning and memorizing them very difficult. The names were also changed based on the will of the botanist describing the plant. There weren’t universal names for each plant, so people around the world couldn’t be certain that they were talking about the same plants.

Once the plants had been given specific names, many benefits were seen.

1. Clarification – each plant had a unique name that was specific to that plant.
2. Universal – everyone used the same name to identify the specific plant.
3. Education – plant names were easier to remember and to learn.
4. Classification – plants were more easily categorized and the categories easier to understand.

Plant Categories

Although the system of classifying and naming plants has changed over the years, its basic structure has remained the same. Today, all living things are classified into kingdom, phylum (or division), class, order, family, genus, and species. This classification is done with the help of DNA sequencing and is overseen by the International Code of Nomenclature (ICN).

Family

Although the binomial nomenclature only includes the genus and species, it is very helpful to also learn which family a plant belongs to. This is a tremendous help in plant identification as plants at the family level often have similar physical characteristics.

From a Biblical standpoint, generally the “kind” refers to the family level of classification, producing after itself.

And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit tree yielding fruit after his kind, whose seed is in itself, upon the earth: and it was so.
Genesis 1:11

Botanical families are named using a Latin plural adjective ending in “aceae”. The adjective usually describes the most prominent genus in the family or the most prominent characteristic of the family.

Examples:
Fabaceae – named after the Faba bean (broad bean)
Iridaceae – from the Greek word for iridescent

Genus

The genera (plural of genus) are groups of plants in a family that are “generic” or “general”. The genera are named using a Latin noun and usually indicate a medicinal virtue or an obvious characteristic of the plant. Names of deities and those who discovered the plant genus are also used.

Examples:
Mahonia aquifolium (Oregon grape) – named after Bernard MacMahon, 19th century American horticulturist

Artemisia absinthium (wormwood) – named after the goddess Artemis in Greek mythology

Species

Species are “specific” plants. They are named using an adjective that describes characteristics specific to that species, the area where that species is native, a person, or after another genus whose characteristics are seen in the species.

Many times the adjective combines two words and ends with a very specific description of a part of the plant.

Word endings include (as well as variations in the endings):
florus – flowers
caulis – stem
carus – fruit
folia – leaves

Examples:
Achillea millefolium (yarrow) – mille means thousand and folium means flowers, so yarrow has thousands of flowers

Leonurus cardiaca (motherwort) – cardiaca refers to the heart, extolling the medicinal use of the plant

Common species meanings:

officinalis – official
vulgaris – common
occidentalis – from the west

Grammar Rules for Naming Plants

Capitalization

Family names always begin with a capital letter and are written in a regular script.

Genus names always begin with a capital letter and are written in italics.

Species names always begin with a lower case letter and are written in italics.

Use in Writing

Generally, when writing or speaking about a plant, both the genus and species are used (thus the term binomial). This is considered the “plant name”.

(Urtica dioica)

If you are writing about several species from the same genera, the genus may be abbreviated using the first letter of the name of the genus as a capital letter with a period after it.

(Mentha piperita, M. spicata, M. pulegium)

If the actual species can’t or need not be named, the abbreviation sp. (or spp. for plural) can be used in its place.

(Scutelaria spp.)

Hybrids are written with the letter x in between the genus and species.

(Mentha x piperita)

Resources:

Botanary
Herbmentor: Think Like an Herbalist – Heather Nic an Fhleisdeir