By Eva Buxton, Conservation & Invasive Species Chair

People who are just getting interested in knowing the names of all the wonderful plants in our surroundings often ask, “Why do you have to use these hard to pronounce and remember scientific names?” This frustration is especially true for those who find learning and retaining names more difficult as they get older. That is certainly true in my case.

The scientific name of a plant consists of a genus (plural genera) name and a specific epithet – together they make up the species name. There are several reasons why using scientific names is essential in many aspects of botany.

Ranunculus acris ssp acris meadow buttercup Amadej TrnkoczyRanunculus acris – Ripeča zlatica from Slovenia – Photo by Amadej TrnkoczyA scientific name is a single, validly published, universally recognized name for each plant. Such a name makes possible the transfer of information and inquiries about a plant from one country to another, sometimes from one State to another in the US. Some of you know that I am Swedish. If I asked questions about “smörblommor,” most would not know that I wanted information on “buttercups.”  Had I instead mentioned that I needed information on Ranunculus, people would have understood my questions and what genus of plants I was interested in. Ranunculus can be found on every continent, from sub-antarctic to tropical to arctic areas and is especially common in temperate and Mediterranean regions. Imagine how many common names are applied to Ranunculus in all the countries where it occurs! Ranunculus is the valid name the world over for plants with a certain suite of characters (characteristics).

Aside: The pervasive and invasive weed in springtime in Marin County called “Bermuda buttercup” is not in the genus Ranunculus. Someone perhaps called it buttercup because of its yellow flower – and it is not from Bermuda either but from South Africa!

Another important reason for using scientific names is that they convey relationships among plants, whereas most common names do not. You would not suspect that sheep sorrel and curly dock belong in the same genus (Rumex) or that Lamb’s quarters and Mexican tea (Chenopodium) are very closely related. Conversely, plants can share common names such as mountain laurel (Kalmia) and bay laurel (Umbellularia), two genera that are totally unrelated. There are exceptions, of course; in California, the name ‘goldfields’ is used for Fremont’s goldfields, Contra Costa goldfields, California goldfields, Seaside goldfields, Smooth goldfields, and others, all in the genus Lasthenia.

Ranunculus peltatus from SwedenRanunculus peltatus – Sköldbladsmöja from Sweden – Photo by Eva Buxton




– Photo by Eva BuxtonAnother reason to use scientific names is that all plants do not have common names, because they are small and “insignificant”, i.e., not showy, are uncommon, or were never assigned common names. (However, all plants with CNPS rarity ranks or listed under the Federal and State Endangered Species Acts have been given common names.) Or often a common plant can have many names. What we in this area refer to as Douglas-fir (Pseudotsuga douglasii) is also called Red fir, Douglas spruce, and Oregon pine elsewhere, doubly unfortunate since Douglas-fir is not a fir, spruce, or pine. And, as with much else, practice makes perfect! If you are a gardener, you probably don’t have too much trouble remembering or pronouncing Aster, Geranium, Pelargonium, Azalea, Rhododendron, Magnolia, Fuchsia, Petunia, Begonia, Chrysanthemum, Penstemon, et al., all scientific genus (generic) names.

Have you heard this one? Two old guys, one from California, the other from Oregon, were bragging about the beautiful trees they had on their properties.

“Mine is a large, evergreen tree with dark, green leaves – a California bay laurel – which provides shade on hot days,” said the Californian.

“Mine is also an evergreen tree – an Oregon myrtle – with narrow, shiny leaves that my wife uses in cooking sometimes,” said the Oregonian.

After bickering a while about who had the most beautiful tree, they parted company. Had they used the scientific name, Umbellularia californica, they would have known they both had the same species in their gardens.