By Camille Stein, Master Gardener Volunteer
Fans of classic films may remember the Gershwin song “Let’s Call the Whole Thing Off,” written by George and Ira Gershwin for the 1937 Fred Astaire and Ginger Rogers film Shall We Dance. The song plays on the way two people can pronounce the same everyday words differently – potato and tomato being the famous examples – until they throw up their hands and decide to call the whole thing off.
Plants have the same problem, only worse. Two gardeners can point at the very same flower and call it two completely different things – and unlike “potato” and “po-tah-to,” the names may not resemble each other in the slightest. Which brings us to a little quiz.
What do these three have in common?
- Broad-leaved paperbark, paper bark tea tree, punk tree, niaouli
- May bells, Mary’s tears, mayflower, mugget
- Gloriosa daisy, yellow coneflower, poor-land daisy
Give up? Each line is a stack of common names for a single plant: (1) the Melaleuca tree; (2) lily of the valley (the first three names are American, “mugget” the British one); and (3) black-eyed Susan.
And that’s just American and British English. Someone may have grown up calling a plant “windflower” in one place, then get a puzzled look at a nursery somewhere else – because there it’s sold as “anemone.” So how do two people who may not even speak the same language talk about the same plant? And how did earlier generations manage it at all?
Enter Carl Linnaeus. Born in southern Sweden on May 12, 1707 (Julian calendar), May 13 (Swedish calendar), or May 23 (Gregorian calendar), he has been called the “Prince of Botanists” and counts among the founders of modern ecology. He was drawn to botany as a boy, and in his school years a local doctor named Johan Rothman showed him that botany was a serious subject and taught him to classify plants by the systems then in use. In 1727, at 21, Linnaeus enrolled at Lund University in Scania, Sweden, and Latinized his first name to Carolus.
After further study and travel, Linnaeus published Species Plantarum in 1753 – the work now internationally accepted as the starting point of modern botanical nomenclature. The first volume appeared on May 24, the second on August 16 of the same year; together they ran to 1,200 pages and described over 7,300 species. In it he laid out the binomial (“two-name”) system: a genus (plural: genera) and a species. He wrote in Latin, then the closest thing to a universal scientific language – and because Latin no longer changes the way living languages do, the names don’t drift over time. Once a plant has its Latin name, that name sticks. The name is written in italics (or underlined), with the genus capitalized and the species in lowercase.
The genus comes first and names a group of related plants; all roses, for example, belong to the genus Rosa. These groupings were – and still are – based on observed similarities. But as we learned that unrelated plants often evolve similar shapes to fit similar niches, it became clear that look-alikes aren’t always relatives. Sometimes new information means moving a plant to a different genus to put it in the right part of the family tree. The species name usually comes along unchanged.
The species name is the second term, and it often offers a clue about the plant. “Multiflora” means “many-flowered,” so Rosa multiflora is the “many-flowered rose,” and Rosa stellata is the “star rose.” But not every species name is a description. Whoever first identifies a new species gets the honor of naming it, and many plants carry the name of the botanist who found them or the region they came from. You’ll see epithets like davidii, wilsonii, or sinensis, each pointing to a person or place in the plant’s history. Come across Buddleja davidii, for instance, and you’re looking at a butterfly bush named for the French missionary and naturalist Armand David. These names add a bit of story to a garden, connecting today’s gardeners to centuries of exploration.
I said a moment ago that once a plant has its genus and species, the name sticks. Well – not quite. Thanks to molecular (DNA) analysis, a lot of species have been renamed in recent years. Plants were once given separate names simply because they didn’t look like anything the namer recognized; DNA can now reveal that two of them are actually the same species, so one name gets retired. This matters because names control access to information. Search only one name and you may miss helpful care guides, older references, the currently accepted name, or shop listings still using the one most customers know. For stores and plant records, the safest bet is often to list both names together – it keeps the plant easy to find while being upfront about which name is current.
Visit a nursery or botanical garden and you’ll spot plants whose names carry several extra words after the species. Those usually mark cultivated varieties – plants bred or selected for a particular trait rather than found growing in the wild. But that’s an article for another time.
Camille Stein is a Master Gardener Volunteer with UF/IFAS Extension Leon County, an Equal Opportunity Institution. For gardening questions, email the extension office at AskAMasterGardener@ifas.ufl.edu.
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