If you enjoy Romance languages, with their shared Latin roots, you are likely to find the botanical names of plants quite swoony. Most botanical names, also known as scientific names, are derived from Latin or Latinized Greek or some hybrid of the two. Yet despite the mash-up of Greek and Latin, it is common parlance to simply refer to the botanical name as the "Latin name." Much is revealed, and often mellifluously, from the small package that is the Latin name.
Tulip Trees and Purple Hedgehogs
The Latin name for tulip trees is Liriodendron tulipifera (Li-ri-o-DEND-ron tew-lip-IFF-er-a). These are the majestically straight and tall beauties such as the ones you find in the woods of the Locust Grove Estate in Poughkeepsie. Their leaves and flowers both resemble tulips.
Liriodendron is Greek for "lily tree" (leirion is Greek for "lily" and is Latinized to "lirio," and dendron means "tree") and tulipifera is Latin for "tulip-bearing." So one could say it's a "tulip-bearing lily tree," although the reference to lilies is not well understood—the tree is in the magnolia, not lily, family.
In the case of the "tulip-bearing lily tree," Liriodendron is the genus, and tulipifera is the specific epithet, pointing to species. The 18th-century Swedish botanist Carl Linnaeus developed that binomial system for naming plants and then proceeded to be the first to describe and name over 7,000 plants. Genus and species were but part of the framework he created for classifying and naming plants and animals, which goes kingdoms > classes > orders > families > genera (singular: genus), and species. Gardeners will be most intent on the family, genus, and species ranks.
Latin names are often very sensually descriptive, as with purple coneflower (Echinacea purpurea). Echinacea comes from the Greek (ekhinos) for "hedgehog" or "sea urchin," referring to the spiky central cone of tiny disc flowers, and purpurea means "purple" and refers (roughly) to one of the most common colors of the ray flowers/petals. I have a patch of those purple hedgehogs that I enjoy greatly, as do the bees in summer and the birds in late fall.
Oftentimes the Latin name either pays homage to a botanist or is named after the botanist who first officially described the plant. For instance, Carl Linnaeus named the genus Zinnia in honor of an 18th-century German botanist and anatomy professor named Johann Gottfried Zinn who accomplished many things in his brief 32 years on Earth.
Other times the Latin name—especially the specific epithet—may refer to the part of the world where the plant was first described by a botanist. So the sinensis in Miscanthus sinensis (maiden grass) tells you that plant comes from China. Magnolia cubensis comes from Cuba and Carpenteria californica comes from California ... and so on.
Rules to Disregard
You'll notice that Latin names are italicized as a means of clearly indicating a scientific name is being given. They stand in contrast to common names, which can be any combination of colloquial words and often differ from region to region. One plant can have dozens of common names and indeed, if I want to call Echinacea purpurea plants "Michelle's purple hedgehogs," no one can stop me. So feel free to invent your own common names...there are no rules. But most plants have only one currently accepted Latin name, and this is helpful to use when you want to be sure everyone's talking about the same plant.
It's normal to feel nervous about pronunciation when you are first learning botanical names. Don't fret about it. I have heard botany professors and horticulturists pronounce the same Latin names very differently. As long as the Latin name a person is using is recognizable, it is not important that pronunciation be precisely the same. Anyone who makes unbidden correction of your pronunciation has too much time on his or her hands.
Sometimes the "correct" pronunciation is notably pretentious. For instance, a fellow grad student insisted I should pronounce Forsythia "For-SCYTHE-ee-a", because it was named for an 18th-century Scottish horticulturist William Forsyth, whose name was said with a long "i" sound. But I and everyone around me have been saying "For-SITH-ee-a" our whole lives. No confusion about the plant in question has resulted, so I chose to ignore my peer's advice.
The Names They Are A-Changin'
Life was simpler for plantspeople in Linnaeus's time. He knew not of cell embryology or electron microscopy. He and his peers organized plant families by morphology, or outward expression, of flower parts. For instance, species in the hibiscus family (Malvaceae, pronounced Mal-VAY-see-ee) were grouped because of similar floral parts. Hibiscus was tied to flowering maple, to hollyhock, and to Rose of Sharon by virtue of shared numbers of petals and sepals, similar ovary contents and position, and so on.
While floral morphology still plays a significant role in determining plant relationships, new techniques examining plants at the cellular level call into question some of those relationships, which in turn affects plant names. And thus the perfectly lovely genus Coleus must now be called Solenostemon, and some species of the elegantly named Sedum must now be Hylotelephium. These particular changes are not sexy.
There are three major reasons for plant name changes: taxonomic evidence, nomenclatural mistakes, and misidentification. Taxonomic changes come about because evidence is found that reclassifies the plant in relation to others. For instance, studies at the cell level of Japanese pagodatree, Sophora japonica, showed that it does not have the same number of chromosome pairs as the other sophoras. Rather, it was found to have the same number of chromosomes and other characters as the styphnolobiums and was renamed Styphnolobium japonicum to join its brethren.
Nomenclatural, or plant name, changes come about to correct errors in spelling or gender matching of the genus and specific epithet, or most commonly, to bring the name into adherence with the rules of botanical nomenclature. Every six years or so, taxonomists hold a conference to update the International Code of Nomenclature for algae, fungi, and plants (ICN) which lays out those rules. "The Code" was most recently reviewed in 2011 in Melbourne, so the current version is referred to as The Melbourne Code and is available online. The International Botanical Congress (IBC), which hosts the ICN meetings, does have the power of "conservation." For instance, when the genus Chrysanthemum was found to be more accurately called Dendranthema, humble appeal to the appropriate committee of the IBC resulted in the conserving of the name Chrysanthemum for at least some economically important members of the genus.
The third major reason to update plant names is to correct errors due to plants being misidentified when they were first named. Styphnolobium japonicum, for instance, was improperly identified as Sophora japonica when the tree was brought into cultivation in the West in the 1700s.
We've established that Latin names are lovely to the ears and rich with meaning. The better plant nurseries have the Latin name on their plant labels, which helps you be sure of what you're getting. Don't settle for what I once saw in a big box store: the plant was labeled "Assorted Landscape Tree."
Common names are fun to play around with, but since they are so numerous and the same common name can be applied to more than one plant, the Latin name is our singular, sweet-sounding lifeline.