Why Plants’ Latin Names Matter

  • Difficulty Rating: Beginner
Flowers closeup

Have you ever heard someone sing the praises of their snowball bush? They speak of bountiful white balls of flowers covering their beloved shrubs. Or maybe you’ve been told no garden is complete without a dogwood. Convinced you must have this magnificent flora, you race to the nursery and declare your need only to have your nursery sales person reply: “Um, there are a lot of snowball bushes and dogwoods…which one do you mean?”

Unfortunately, learning plants by common names leaves us poorly equipped to shop for them successfully. The problem with common names is that they are used for more than one plant. In the case of the snow ball bush, immediately two plants that go by this name come to mind: Hydrangea and Viburnum. And, I’ll bet there are more. As for dogwoods, you could end up coming home with a ground-hugging spreader, a twiggy bush or any number of flowering trees. Common plant names may seem easier to remember, but they can mean trouble as your garden grows.

 

Plants and dirt near sidewalk

 

In the 18th century Swedish Botanist Carl Linneaus set out to use Latin – the then language of science – to create a naming system known as binomial nomenclature. This system of Latin or Scientific Names became a two-word classification technique that standardized names worldwide and enabled botanists to categorize plants by distinct characteristics – breaking them down into genus category and from there into species within a genus.

Employing this naming system, gardeners and botanists now had the power to differentiate a Viburnum (genus name) snowball bush from a Hydrangea (genus name) snowball bush. Then, by looking more deeply at plants within a genus, they were able to begin building classifications of species within each genus. So now not only would you be able to go to the nursery and ask for a Viburnum, but you would also have the ability to ask for a Viburnum opulus that flowers in snowball puffs in summer, gets lovely fall color and loses its leaves in winter. This instead of being handed any Viburnum and risk getting a short, evergreen Viburnum davidii whose blooms aren’t very snowball-like at all.

In addition to looking at the genus and species, it is important to consider some additional naming specificity including variety and cultivar designations.  Variety will refer to a naturally occurring variation that has arisen in the plant from generation to generation and generally holds true over time – but there’s no guarantee that this variation will be everlasting. Cultivar refers to a cultivated or forced variation that is known to be enduring. A plant with a named variety is written:Genus species variety; a named cultivar is written: Genus species ‘cultivar’.

So, if you want to be sure you get yellow twig dogwood instead a red one, you would write Cornus sericea ‘Flaviramea’ rather than Cornus sericea 'coloradensis' (among other options). Whenever possible, to be on the safe side, ask for a cultivar by name and avoid surprises like a blue conifer fading to green as it ages.

 

Brush on side of walking path

 

Mondo Grassis a common name used for a number of plants including the genus Ophiopogon. Ophiopogons are fantastic evergreen, strappy-foliaged flowering perennials, but as the plant name lengthens, there’s more to learn. Ophiopogon planiscapus ‘Nigrescens’ (commonly known as Black Mondo Grassis) is very different from Ophiopogon japonicus ‘Nana’ (Dwarf Mondo Grassis). The former is larger with black foliage; the latter is much smaller and green. Ordering them by their full name, including cultivar name, ensures that not only will you get what you’re looking for, but you will also get a plant that remains true to form for the duration.

Classification systems get even more complicated with cross-species hybrid names or cross genus hybrids. And, the reality is that plants are constantly being reclassified into different and even new genera all the time. Plus, with the advent of DNA mapping, it is quite likely that names may completely change again in the not-too-distant future. Fortunately, if you’re able to provide your plant sales person with a relatively current scientific name, you’ll find yourself with just the right snowball bush, mondo grass or dogwood (tree, shrub or ground cover) to fit your needs.