If you’ve been thumbing through a gardening catalog or shopping at a nursery, you’ve likely noticed two names assigned to each plant, a common name and a botanical name, the latter of which might read like a sort of pretentious, unpronounceable gibberish.
That’s botanical Latin, and its purpose is to help you confirm that the plant you bring home is what you intend to buy.
The common name can get you into trouble. That’s because common names are just nicknames for plants. A single common name can be shared by many plants. And one plant can have many common names.
Confusion often ensues.
The perennial cranesbill, for instance, is the true Geranium, while the annual container plant that carries the common name geranium is actually a Pelargonium. And depending on where you live, you might know my favorite perennial as blazing star or gayfeather. But call it Liatris spicata, and everyone in every region and country will know which plant you’re talking about.
This name game was first addressed in the 1700s by Swedish botanist, zoologist and physician Carolus Linnaeus. His works “Systema Naturae” and “Fundamenta Botanica” created rules for classifying and naming plants in botanical Latin — a language he made up, and with which all gardeners should have at least some familiarity.
Linnaeus devoted his life to assigning every plant and animal of his time a two-part, or binomial, name consisting of a genus and species, often based on the appearance of their reproductive parts. As you might imagine, some of those names raised 18th-century eyebrows.
Linnaeus’ International Code of Botanical Nomenclature dictates that a plant name start with a capitalized genus, followed by a lower-case species, then either a variety (if naturally occurring), cultivar (if created by a breeder) or hybrid name (if it’s a cross between two plants, indicted by an “x”).
The code is regulated by the International Botanical Congress, which has been convening every six years since 1900 to evaluate and decide on naming issues raised by new genetic research and scientific findings. After all, Linnaeus didn’t have a microscope or DNA testing lab, which would have helped definitively determine which plants were related.
The Congress, which meets next in Madrid in July 2024, uses these modern tools to decide which plants to reclassify or rename.
Bleeding hearts, once officially called Dicentra spectabilis, were moved into the newly created Lamprocapnos genus several years ago, and snapdragons, originally in the Antirrhinum genus, were transferred into the plantain family, Plantaginaceae, along with Digitalis, Hebe and Penstemon.
But nobody regulates common names, and that can turn plant identification into a Tower of Babel, where Rudbeckia hirta is known to some as black-eyed Susan, to others as yellow-oxeye daisy and to others still as gloriosa daisy.
And the potential for error doesn’t end there, as when the same common name is shared by several plants. Ask a garden center employee for a snowball bush, and you might walk out with Hydrangea arborescens or Viburnum plicatum.
So it pays to study up — or at least do a little research before buying plants or swapping seeds.
Plug a common name into the Royal Horticultural Society’s free online Garden Plant Finder (www.rhs.org.uk/plants/search-form) and get a listing of relevant botanical names — or vice versa. And if you really want to nerd out, lose yourself in the International Plant Names Index (www.ipni.org), a collaboration between The Royal Botanic Gardens, Kew; The Harvard University Herbaria, and The Australian National Herbarium.
