by What Linnaeus Saw- A Scientist's Quest to Name Every Living Thing (retail) (epub)
Sometimes a common name hinted at what a plant looked like, where it came from, or how it was used.
But they were not good identifiers. Since plants provided food and most medicines used by humans, correct identification could be a matter of life or death. Some plants could make people healthy. Others could kill them. They needed to know which was which.
Often scientists in different places came across the same species. Each concocted a name for the plant. The result was that most plants wound up with a slew of scientific names in a variety of languages. The mishmash of names was confusing. For instance, one naturalist called the common wild briar rose Rosa sylvestris inodora seu canina, while another called it Rosa sylvestris alba cum rubore, folio glabro.
As explorers sailed home with boatloads of strange plants from foreign lands, the need for precise names to tell them apart became more urgent. So scientists coined names that were more informative, and that meant they grew even longer. By the eighteenth century, Aristotle’s “asparagus,” from the third century BC, had morphed into Linnaeus’s long descriptive name, Asparagus caule inermi fruticoso, foliis aciformibus perennantibus mucronatis termis aequalibus. This was not just any asparagus; it was the one with a “spineless stem with shrubby, needle-like perennial leaves ending uniformly in short, sharp points.”
Names served two purposes. They were full scientific descriptions—leaves, stems, roots, flowers, fruit, uses—and they were also labels—what you called the plants, how you referred to them.
What science needed was a consistent system of naming that could be understood by scientists all over the world. However, researchers conducted fieldwork in the natural environment away from their workrooms and reference books. What researchers needed were names that were easy to remember and quick to write. This crisis of names was evident when Linnaeus lived in Holland, but the solution was not. Botany would have to wait, there being something more urgent brewing in Linnaeus’s own life.
In 1738, Dr. Boerhaave, wanting Linnaeus to settle in Holland, offered him the chance to join a Dutch expedition to the Cape of Good Hope and South America with the promise of a professorship afterward. Linnaeus turned him down. He was anxious to return to his fiancée. His three years were almost up, and he had heard that someone else was seeking to court Sara Lisa.
Linnaeus returned to Sweden, set up a medical practice in Stockholm, and began treating patients. On June 26, 1739, Carl Linnaeus and Sara Lisa Moraea said “I do” at her parents’ home.
Two years later, in May 1741, Linnaeus succeeded his old professor, Olof Rudbeck the Younger, as professor of medicine at Uppsala. In October, he and Sara Lisa moved with their infant son, Carl, into the late professor’s house. Dr. Rudbeck had left it as messy as “an owl’s nest.” They cleaned it up, modernized the house, and Linnaeus delivered his inaugural lecture on the importance of travel within one’s own country.
In the midst of all the other work, Linnaeus began the big job of renovating and reorganizing the garden. This was the garden where he’d introduced himself to Professor Celsius, where he’d led his first demonstration as a second-year student to an enthusiastic crowd, and where he would be inspired and employed for the rest of his life. He’d had enough of trekking in the Arctic and traveling abroad. He never set foot outside Sweden again.
Carl Linnaeus and Sara Lisa Moraea at the time of their wedding in June 1739.
Carl Linnaeus’s most lasting contribution to science would be his system for naming species. Like twentieth-century computer programmers who built search engines to find information on the internet using keywords, Linnaeus created a simple way to make a massive amount of information easily searchable—using keywords. At the time, he had no clue how revolutionary his idea was. For Linnaeus, it was no more exciting than a handy shortcut.
THE CHILDREN
Carl and Sara Lisa had five children who lived to adulthood: a son, Carl, and four daughters, Lisa Stina, Lovisa, Sara Stina, and Sophia. They lost two further children: Sara Lena, who died at two weeks, and Johannes, who died of fever at age three. When Sophia was born after a difficult labor, there were no signs of life. Linnaeus fought to save her, trying mouth-to-mouth resuscitation and then insufflation, a treatment in which medicinal smoke was blown into the nose. Finally, after fifteen minutes, the baby took her first breath. Sophia would always have a special place in his heart. As a toddler, she often walked across town with her father, his handkerchief tied around her head, to the university’s lecture hall, where she would stand between her father’s knees as he taught.
All the children heard their father’s conversations with students, whether in the garden, at the supper table, or in the upstairs lecture room at home in Uppsala. But as was common then, boys were treated differently when it came to education. Linnaeus enrolled young Carl in the university at age nine. Girls did not usually attend school, and Linnaeus’s daughters were no different. Once when her husband was away, Sara Lisa enrolled Sophia in a school. When he returned, he took her out again. But he taught his daughters to read and write, and some botany.
One of the girls showed both special interest in her father’s plants and a scientific aptitude. On a summer evening at Hammarby, right at dusk, Lisa Stina, then nineteen, noticed sparks of light, like tiny lightning flashes, emanating from nasturtium flowers in the garden. She made observations several nights in a row. Even though others who watched with her corroborated her story, Linnaeus, who’d been out of town, wasn’t convinced until he saw the nasturtiums himself on two consecutive nights. He encouraged Lisa Stina to write up her results as a scientific paper, and it was published by the Royal Swedish Academy of Sciences. The famous German author Johann Wolfgang von Goethe, an admirer of Linnaeus, named the phenomenon after her. The effect was thought to be electricity passing through the flowers, but years later, the flashes were proved to be an optical illusion—caused by the way our eyes discern the flowers’ colors at twilight—not bioluminescence.
Nobody knows exactly what inspired him. The idea might have sprung from confused reports sent in by the first generation of young globetrotting Linnaeans busily exploring the world’s wild places under extreme conditions. Or the idea might have been due to a farm study conducted around Uppsala. Either way, even the complex name-phrases that Linnaeus himself had so carefully crafted were still as many as twelve Latin words long. Wherever his students were, the lengthy names made it hard for them to keep track of plants. Their field notes were a muddle.
The farm study was conducted in 1748. Thirty exuberant students traipsed through tall grass after cows, goats, sheep, horses, and pigs. Their job—to identify plants eaten by the animals and those avoided—was not easy. Which plants did goats prefer to eat? Which did sheep steer clear of? Did the pigs, true to their reputation, eat everything in sight?
Questions about what animals chose to eat had intrigued Linnaeus since he made an expedition to the Swedish province of Dalarna and the Norwegian woods along its border in 1734. There he noticed that the pack horses, tethered in lush pasture, devoured most plants but avoided valerian, lily of the valley, loosestrife, and others that would be toxic to them. The horses seemed to easily recognize healthy food from noxious.
On the other hand, every spring in Sápmi, where the harsh climate made forage plants scarce, whole herds of cattle suffered excruciating deaths. No one could explain the mysterious losses. Nervous farmers blamed toxic water, spiders, or a return of the plague. After days of searching their pastures, Linnaeus had diagnosed the cause of death as poisonous water hemlock. The cows, ravenously hungry for fresh green food after months of dry winter feed, grazed outside. He inferred that they were unable to detect the hemlock’s telltale turnipy smell underwater in the wet springtime soil.
Linnaeus guessed that farm animals, when not overly hungry, would choose wholesome plants over toxic ones, as the expedition horses had done in Norway. By pinpointing plants preferred or avoided, his team could advise farmers which plants would raise the healthi
est, most useful livestock for farm work and market.
Sweden was a nation of farmers. What livestock ate mattered to everyone. Since it was then commonly assumed that plants, animals, and minerals were resources put on earth by God for the benefit of humans, Linnaeus believed a central purpose of natural science was to aid the economy. “An economist without knowledge of nature,” he claimed, “is like a physicist without knowledge of mathematics.” Sweden’s faltering economy, the result of years of costly wars with its neighbors, was always in the back of his mind.
The study was straightforward. Each student was assigned one type of animal. Nineteen-year-old Pehr Löfling focused on goats. To record plant names, he and his classmates each carried an inkpot, pen, and paper, and possibly their professor’s new 420-page field guide to native Swedish plants. This book included eleven hundred plants and gave each a full scientific description.
With the livestock roaming from place to place as they ate, Löfling and his fellow students had to look up and write down phrase-names, literally on the run. They knew many one-word genus names like Achillea, Rudbeckia, and Salvia, but it was impossible to memorize all the lengthy strings of Latin words that came after.
For instance, when a goat ate a dandelion, Löfling hastily copied down the name:
627. LEONTODON calyce inferne reflexo
This genus name, Leontodon, or “toothed lion,” referred to the dandelion leaf’s jagged shape. The rest meant that the flower’s calyx, or leafy covering, was bent backward in the lower part. This time Löfling got off easy. At only four words, it was one of the shortest.
The students’ frustrations no doubt reminded Linnaeus of his own childhood struggles trying to learn complicated Latin plant names. One summer, as a four-year-old, he hiked with his father, Nils, through the woods and fields to a neighborhood picnic on the other side of the lake. Every few steps he begged for the name of a plant. What’s this? What’s that? His father answered patiently . . . until the boy asked about the same plants over and over again. Nils warned that he would stop telling him the names if he did not start remembering them. The little boy put his mind to it, and before long he knew every one.
A page from Linnaeus’s field guide to Swedish plants. Entry 627 was one species of dandelion. After each descriptive name, he inserted descriptions by Vaillant, Tournefort, and other botanists. Then he listed common names. For instance, the French name piss en lit, meaning “wet the bed,” came from the practice of giving dandelion tea, a diuretic, to children early in the day to prevent bedwetting at night. Linnaeus also included the habitat of each plant and its pharmaceutical uses. Entry 628 was a different species of dandelion.
Linnaeus empathized with his students. He had been experimenting with a way to speed up their note-taking. He showed them his shortcut: just the genus name plus its number from the field guide.
So now, as young Löfling chased after a goat to figure out which of the three dandelion species it was eating, he scribbled:
Leontodon, No. 627
This was a little easier than before, but Löfling still had to look up the number while he was in the field. Later he would use the number to look up the full name for his final report.
In the meantime, the students scrambled to outdo one another. They kept track using a code:
1 – for a plant the animal ate;
0 – not eaten;
1 + 0 – sometimes eaten, sometimes refused;
1 0 – eaten fresh but not dried;
1 1 – eaten with great pleasure.
Pehr’s goats especially enjoyed blue fieldmadder, with its little blue flowers, and queen of the meadow.
The team conducted 2,300 tests, some repeated as often as twenty times. Pehr Löfling, for instance, checked his results by mixing a test plant into a pile of known goat-favorites. Of all the animals, the goats were the least picky eaters. Which were the most selective eaters? Surprisingly, the pigs. They turned up their snouts at 171 kinds of plants and ate only 72.
When the students turned in their reports, Linnaeus prepared a chart. Using the same codes they had used, he tabulated the results in separate columns for cows, goats, sheep, horses, and pigs. To list the plants, in the first column he wrote a number. In the second column, next to the genus, he wrote one word, usually an adjective, for each of the species in that genus:
[#] [Genus] [species] 627. Leontodon taraxacum
He looked for a key adjective in each existing lengthy description in his field guide. He wanted a single distinctive word that pertained to one species of plant and was unique to that species only and easy to remember. It was supposed to be a temporary nickname.
After the study was complete, Linnaeus continued to experiment with names. Then he streamlined the shortcut: he dropped the number entirely. This left two words, the genus name followed by one word. Together, these two key words became the binomial (from Latin, bi- meaning “two,” and -nomial meaning “name”). The first word described the whole group, or genus, and the second word limited the name to one member of that group, the species. The second word was often a physical or geographic characteristic. It was simpler to remember than a number. This made his students’ fieldwork quicker and easier. It eliminated the need to lug around a field guide.
Linnaeus’s notebook from the farm study. Columns show the eating preferences of cows (Boves), goats (Caprae), sheep (Oves), horses (Equi), and pigs (Sues).
Binomials had been used before; Linnaeus didn’t invent them. However, he was the first to apply them consistently. What he did was standardize the naming process and make it universal. Previously a scientific name had served as both a name and a full description. Linnaeus separated those two functions. Now the name was only a label. It had only one job. There was no need to scribble down details out in the field.
This change also separated the collecting of information from its analysis. Again Linnaeus was shaking up another long-standing way in which he and his fellow scientists worked.
He explained that adding the species name to the genus was like putting “a clapper into a bell.” Without a clapper to strike the bell, a bell makes no sound and cannot do its job. The second word called out clearly one distinguishing feature of each particular species. Acer rubrum, red maple. Theobroma cacao, “food of the gods,” cocoa. Citrus sinensis, sweet orange (sinensis means “Chinese”). Even the potato got a new scientific name. In his nomenclature, the official scientific name was Solanum caule inermi herbaceo, foliis pinnatis integerrimis. Its new nickname was simply Solanum tuberosum, “fleshy tuber.”
Five years later, in his book on the species of plants, Species Plantarum (1753), Linnaeus listed the full descriptive plant names in alphabetical order together with their simple two-word nicknames: the genus name plus what he called a trivial name for the species. He had often chosen them quickly. That he called it “trivial” shows how unimportant he thought this shortcut was. He still considered the longer version to be the one true and permanent name. Not everyone agreed with Linnaeus’s ideas, but more scientists began using his system, and its popularity soared. For the first time in history, a scientific name would be consistent and universal no matter which country was home to the scientist who coined it.
Linnaeus set rules for creating both genus and species names. The format was always the same:
Genus + species = binomial name
The genus name was like a person’s last name—for example, Lincoln—which is given to all the members of a particular family. The species name was like a person’s first name, given at birth—Abraham, for example—which distinguishes that child from all the people related to him, in other words, from his parents and siblings who share the same last name. To Linnaeus, species were the basic units of life. The scientific name was presented “last name, first name.” Lincoln, Abraham.
In addition, all Linnaeus’s descriptions were written in the same scientific language, based on Latin and Latinized Greek root words. He spelled out scientific definitions an
d listed rules for creating standardized names, such as this one:
Names used by the ancients, that are 1-1/2 feet long, and which constitute descriptions instead of definitions, are to be abhorred.
He kept many established genus names but avoided those that “are difficult to pronounce.” Some scientists had concocted names by lumping together several Latin and Greek descriptive words into a single word. These were very long. Linnaeus warned that words with more than twelve letters or several pairs of consonants were “liable to damage the throat of the speaker.” He even gave examples: Hypophyllocarpodendron, Coriotragematodendros, Acrochordodendros, Stachyarpogophora, and Orbitochortus. He also ruled out “disgusting” names and gave examples. One plant, when crushed, gave off an awful odor. Somebody had named it Galeobdolon. The name meant “weasel-stink.”
The names did not always describe physical properties. He often demoted old genus names, such as Galeobdolon, but preserved them as species names so apothecaries would still recognize plants they commonly used to treat illnesses. Since he had to come up with thousands of distinct names for plants and animals, his prolific reading sometimes fired up his imagination. He called butterflies after gods in Greek and Roman mythology and heroes of the Trojan War. He named plants after important botanists—living and dead—and his students. He frequently used names to celebrate people who had discovered the species.
Colleagues and his intrepid student-travelers shipped him boxes, crates, and packets of new species and seeds from distant places. They were dispatched from Indonesia, India, Egypt, Syria, Cyprus, Turkey, Yemen, and Iran; in Europe, Slovenia, Spain, Italy, Russia; and in the Americas, Suriname, Colombia, Venezuela, the West Indies, Pennsylvania, Virginia, Quebec. He rewarded some contributors by naming a plant or animal genus after them—such as the fragrant tropical shrub Gardenia, after naturalist and colonial physician Dr. Alexander Garden of Virginia. Then there were Bartramia, Coldensonia (after Jane Colden’s father, not Jane), and Collinsonia.
