Essential Oils and Botanical Names – are they really that important?

For aromatherapists, it makes knowing what you’re buying clearer. Choosing a different essential oil based on the common name can have detrimental impact on the client.
It could mean that you use an essential oil that doesn’t have the same therapeutic effect as you’re expecting, and even worse, could be potentially unsafe.

Posh word. But what does it mean? According to the Convention on Biological Diversity, “Taxonomy is the science of naming, describing and classifying organisms and includes all plants, animals and microorganisms of the world. Using morphological, behavioural, genetic and biochemical observations, taxonomists identify, describe and arrange species into classifications, including those that are new to science.”

Binomial nomenclature is a system that is used to name plants. In his work ‘Species Plantarum’, Swedish botanist Carl Linnaeus described in Latin all the plant species known in the world at that time. He introduced the binomial (two-name) system of nomenclature to identify, name and classify not only plants but animals too, and is often referred to as the Father of Modern Taxonomy.

As of July 2022, Kew Gardens state that there are 387,703 different plants that have now been identified, classified and named, and new ones are being discovered each year.

The entire plant kingdom is divided up into a number of classifications. Plants are grouped together according to similarities (botanical families) and these are subdivided according to other similarities of the plants in that group (genus). These are then divided into species and sometimes species can be subdivided (subspecies or varieties) when there are variants of a species.

So, the name of every plant species is made up of two words: the genus and the specific epithet. The names give an idea and description of the plant itself. For example, cypress is Cupressus sempervirens, and sempervirens means always green or evergreen. Sweet orange is Citrus sinensis and sinensis means from China.

Let’s look at an example from the animal world. Can you guess what a Panthera leo is? This is the scientific name for lion. Leo unsurprisingly means lion, and panthera is a genus of the Felidae (cat) family comprising of lions, leopards, jaguars, snow leopards and tigers.

What else?

Sometimes you’ll see ‘var’ as part of the botanical name. This is the abbreviated form of ‘variety’ or in Latin ‘varietas’. This is a further division given to certain plants that share the same genus and specific epithet, but are deemed to be sufficiently different to be named as varieties of the same species.

So, for example, there are two types of orange essential oils on the IFA Aromatherapy Diploma syllabus: a bitter variety and a sweet variety. But the plants are sufficiently similar to be classified under the same genus and specific epithet. So Citrus aurantium var amara refers to bitter orange, and Citrus aurantium var dulce refers to sweet orange. Sweet orange also has a synonym: Citrus sinensis as mentioned earlier.

Have you ever come across botanical names that have an ‘x’ as part of the plant species and wondered what this means? This indicates that it’s a hybrid. i.e. a cross between two different plants species. For example, Citrus x paradis, which is grapefruit, is a hybrid of Citrus maxima (pomelo – who doesn’t love a Thai style pomelo salad?), and Citrus sinensis (sweet orange).

How about ‘ct’? This is an abbreviation for chemotype and refers to essential oils that are produced from the same plant species, but because of where the plant has grown they produce essential oils containing different chemical compounds or different quantities of the same or similar chemical constituents. Here are a few examples of essential oils that have chemotypes: Melaleuca viridiflora (niaouli), Salvia Rosmarinus (rosemary), and Thymus vulgaris (thyme).

Let’s take a look at rosemary, which by the way, was reclassified from Rosmarinus officinalis to Salvia rosmarinus in 2019. Science now shows it has more in common with sage and has been absorbed into the Salvia genera.

We have Salvia rosmarinus ct cineole, Salvia rosmarinus ct camphor and Salvia rosmarinus ct verbenone. All are extracted from the same plant species, but because the plants from which they’re produced have been grown in different countries, in different climactic conditions, in different soil, perhaps even being harvested in different ways, they produce essential oils with variable chemical compounds and quantities of those compounds.

And finally

You may have come across a botanical name that looks something like this:

Lavandula angustifolia (L.) Mill. (commonly known as lavender).

‘Mill’ is the abbreviated form for ‘Miller’ denoting the botanist/author who first described and published the name of plant species. The (L.) is abbreviated for Linnaeus denoting that this is one of the plants that Linnaeus originally classified using binomial nomenclature.

Hope that’s cleared the fog away for you and made the complex topic of botanical names a bit clearer.
Enjoy exploring the wonderful world of essential oils and aromatherapy