by What Linnaeus Saw- A Scientist's Quest to Name Every Living Thing (retail) (epub)
His professor, Olof Rudbeck the Younger, was celebrated in the name of the black-eyed susan, Rudbeckia. Linnaeus named another genus Celsia, after his mentor Olof Celsius and his nephew Anders.
He named the mountain laurel Kalmia after his student Pehr Kalm, who explored North America. He named a tropical Spanish plant Loeflingia after Pehr Löfling, the enthusiastic young goat-herder who later died while exploring Venezuela. And he named a beautiful umbellate plant Artedia after his dear friend Peter Artedi, who had been fascinated by the umbrella-like plants. Native to Cyprus, Israel, and the eastern Mediterranean, this annual—meaning it lasts only a year—was short-lived like Artedi. Also like its namesake, the genus Artedia contained only one species; it was one of a kind.
Sometimes names told memorable stories. A plant that could not tolerate too much water was named after Elias Tilliander, an Uppsala student who was so terrified by a stormy crossing of the Gulf of Bothnia that, on his return trip home, he traveled by land—an extra 1,800 miles—and changed his name to Tillandz, meaning “by land.” Tillandsia, commonly called an airplant, grows attached to other plants and takes moisture and nutrients from the air.
During his lifetime, Linnaeus described and coined names for 7,700 plant and 4,400 animal species. He insisted this system be founded on direct, firsthand observation. So he studied each species using live or preserved specimens, drawings, and descriptions made by trusted global correspondents. He grew many rare plants in his own gardens. He peered through a microscope to name an amoeba Chaos chaos, Latin for “shapeless mass.”
Linnaeus’s landmark two-part name format was not an invention. It was actually a technological tool. What made it different from the two-word folk names already used by people around the world? Linnaeus’s scientific names were precise, consistent, and in a single universal language. Since it was Latin, he expected all scientists would be able to understand it, no matter what language they spoke in their everyday lives. Plus, he used a common vocabulary with definitions that were standardized and consistent.
This naming system was a convenient way of organizing data so that information could be found more quickly. Binomial nomenclature—two-word naming—was an indexing tool that vastly simplified work. Linnaeus was making the most of his student support staff, and those hardworking students were grateful. Now they could finish more work in less time.
There was one plant that stumped him, though. What could he call a plant that was troublesome beyond words?
Monster.
Herbarium specimen sheet from the Natural History Museum, London. Linnaeus named this umbellate plant Artedia squamata for his late friend Peter Artedi.
INNOVATIONS IN PAPER TECHNOLOGY
Linnaeus had to sort through and describe the constant rush of incoming plants, animals, and information. Despite taking quick power naps to refresh himself, the workload was stressful. He told a friend, “I feel like a tired horse who does not feel like obeying the whip.” Over the years, he simplified his task by coming up with several paper technologies which changed the way botanists kept track of information and specimens. While they look obvious now, at the time they were revolutionary.
His first innovation was the use of loose herbarium sheets. For years, Linnaeus and his fellow botanists had glued dried plant specimens, two or three to a page, then bound them together as books. The problem was that newly found plants could not be added into books that were already bound, and the order in which the plants were arranged couldn’t be changed. New specimens required new books.
Using isinglass, a paste made by boiling out a gooey substance from the swim bladders of freshwater sturgeon, Linnaeus began placing one specimen on a sheet. Only one. And he left the pages loose.
A second innovation was his cabinets. In order to organize all those loose sheets of paper, Linnaeus hired a local woodworker to build three eight-foot-tall cupboards, 16 inches wide by 12 inches deep, with folding doors. Each cupboard could hold 6,000 loose sheets of paper, which meant 6,000 dried plant specimens. Linnaeus could relocate a plant to make room for the steady arrival of new discoveries at any place within the system.
Later in life, feeling overwhelmed by “information overload,” Linnaeus came up with a more flexible way of looking at large masses of data. His third innovation was to cut paper into little slips 3 x 5 inches (7.5 x 13 cm). At the top of each slip, he wrote a genus name, then briefly described one species. He could file these, easily change their order, or spread them out on a table to analyze relationships. Today we call these slips of paper index cards.
In a time- and paper-saving innovation, Linnaeus began in 1751 to use the alchemical symbols that he had learned as a child in a new way—to indicate gender in plants. These symbols were letters from an ancient alphabet that medieval alchemists had adoped to abbreviate the names of metals.
For male, Linnaeus used the symbol for iron, the hard metal that alchemists associated metaphorically with Mars, the god of war and agriculture.
For female, he used the symbol for copper, the softer metal they associated with Venus, the goddess of love and fertility.
He was the first to use these symbols in the biological sciences.
Examples of Linnaeus’s “index cards,” paper slips used to record and organize information as he prepared the twelfth edition of his book Systema Naturae in the 1760s.
NAMES NOW
Linnaeus’s book Species Plantarum, published in 1753, is considered to be the starting point for modern botanical naming. Any plant name used before the book’s appearance became obsolete—even those coined by Linnaeus himself. In his tenth edition of Systema Naturae, published in 1758–59, he also established binomials for animals. That book became the starting point for modern zoological naming. By convention, the names are italicized. The genus name is capitalized and comes first; the species, uncapitalized, comes second. Even today, Linnaeus’s system means that a scientist anywhere in the world, speaking any language, can use a two-word scientific name to find exactly the right plant or animal. The beauty of the system is its simplicity.
Three hundred years after Linnaeus’s landmark innovation, botanists continue to change names and groupings as they learn more about genetic relationships through DNA testing, gene mapping, and other modern technological advances. But the majority of the thousands of plants described by Linnaeus are still recognized by the names he gave them.
History can be seen in the names themselves. Each one officially ends with the name or abbreviation of the person who coined it. Many are still followed by the simple, most famous initial of all: “L.”
8
THE MOST CONTROVERSIAL PLANT
Fantastic . . . unparalleled in botany . . . no less remarkable than if a cow gave birth to a calf with a wolf’s head.
—CARL LINNAEUS, DISSERTATION, “PELORIA,” 1744
“Here is something remarkable.”
The note came tucked in a package from Linnaeus’s colleague and old friend Olof Celsius. Inside, a pressed plant was glued onto an herbarium sheet.
Just an ordinary linaria, Linnaeus thought at first. Nothing special. It was native to many parts of Europe. Folks who spoke English called it toadflax, Jacob’s ladder, or butter-and-eggs. In Sweden people knew it as gulsporre, meaning “yellow spur.” It popped up everywhere along dusty cartways and in dry, rubbly fields. This was hardly a “remarkable” find.
But on closer examination, the flowers were all wrong. They looked as if they had been turned inside out.
It was the fall of 1742, and one of Celsius’s students claimed he had found it while scouting specimens over summer vacation. He lived on South Gåsskäret, a speck of an island in the archipelago of 24,000 islands that dot the Baltic Sea off Stockholm’s rocky coast.
In only his second year as a professor at Uppsala, Linnaeus was already considered the expert. Despite his commanding knowledge of flowers, this one stumped him. He was suspicious. Maybe it was a practical joke—flowers plucked from some other spec
ies and glued onto an ordinary linaria stem? Students often pulled pranks and Linnaeus was known to enjoy a good laugh. This would not be the first time somebody had tried to fool him. Maybe the plant had come from the Cape of Good Hope, Japan, or Peru. He found it hard to believe it had come from Sweden, whose plants he knew so well.
Normally a linaria flower had one cone-shaped spur. The spur was like a bottle into which a bumblebee would stick its strawlike proboscis for nectar. To reach the spur, the bumblebee first had to squeeze through the petals into the flower. Once inside, it pushed its way past stamens loaded with pollen, and the dusty yellow pollen brushed off onto its fuzzy back. When the bee entered the next flower, the pollen from the first flower rubbed off the bee’s back onto the second flower’s sticky pistil, pollinating it. Then and only then could the flower’s seeds develop. That was how it was supposed to work.
However, when Linnaeus inspected one of these strange flowers, things were different. Instead of one spur, as in a normal linaria flower, there were five, like the arms of a starfish! Instead of halves that mirrored each other (like a chair), it had identical parts radiating around a center point (like a stool).
A common linaria with normal flowers, each with one pointed spur.
The mystery plant peloria with closed-up petals and five spurs on each flower, as pictured in Linnaeus’s dissertation.
More importantly, the petals were not open for the bumblebee. They were sealed up, as tight as a Sami drum. There was no way for a bee to get inside to feed on nectar. Since the bumblebee could not pollinate the plant, Linnaeus assumed that the plant could not reproduce. So where did this plant come from? How could it even exist?
On the outside, he saw no evidence of a trickster’s glue holding the flowers to the stem. When he dissected one of the flowers, what he found was equally strange. Inside was an internal structure he had never seen before in any other plant in that genus.
What Linnaeus had expected to find was two long and two short stamens. This would have meant it belonged with snapdragons, foxgloves, and other plants with four stamens in the genus Antirrhinum, the class Didynamia. But this flower had five stamens all the same length. He tried fitting it with other plants with five stamens, but it was nothing like the potatoes, primroses, heather, and others in that class either.
This was a head-scratcher. The bizarre plant broke all the rules he had laid out so carefully. His system was based on flower structures which he found repeated in plants from all over the world. Every flowering plant fit into these standard patterns . . . until this one. It did not fit anywhere. What could explain this mystery?
Linnaeus considered three options:
1. A species never seen before? Highly unlikely. Since Linnaeus and his fellow botanists knew almost every kind of plant growing in Sweden, he confidently ruled out that it was previously undiscovered.
2. A hybrid plant? Possibly. Scientists at the time recognized the existence of animal hybrids like the mule, the result of the union of a donkey and a horse. However, there was little discussion about whether the pollen of one plant could fertilize a different kind of plant. There was no talk of whether such a union could produce a new plant species.
To be considered a species, a living thing had to be able to produce young like itself. Since the mule was sterile and could not produce little mules like itself, this animal hybrid was not a species. Therefore, the mule was no threat to the widely-held belief called the “fixity of species”—that all the plant and animal species in the world were created by God at once at the beginning of time. Most eighteenth-century Europeans held this basic view of the natural world. Linnaeus had learned it from his father. It was taught in every school he ever attended. He himself taught it to his own students.
3. A newly created species? Highly unlikely—unthinkable even.
Celsius’s student confirmed that these strange plants were thriving in their island habitat. This meant to Linnaeus that the plants must be fertile, because they were producing similar young plants somehow. If this was a fertile hybrid, it would have to be a brand new species . . . one that had come into existence after Creation. Most people at the time considered this impossible. To say otherwise would have been dangerously close to heresy. Pursuing this radical idea would present big, messy complications for Linnaeus, both personally and professionally.
It was like running in the dark along the edge of a cliff. Linnaeus did not know where it would take him. It was unsettling.
Linnaeus wanted to see a live specimen. However, he did not visit the island site himself. Perhaps this was because traveling to the island would have taken a couple of days and this was the start of the school year, always a hectic time. Plus, the plant bloomed in late summer, and autumn was creeping toward winter. It is even possible he did not want evidence that would confirm his troubling suspicion that this could be a new species. No one knows why he didn’t go.
Instead, he asked Celsius’s student to return to the original habitat as soon as he could and, this time, dig up living plants with roots attached. He needed answers.
When the live specimens arrived, he immediately transplanted them in the university botanic garden. He watched and waited as their tender roots took hold. The plants survived just long enough to be studied.
During the next two years, Linnaeus agonized over what he thought he had seen and what it could mean. He wondered whether this was a fertile cross between a common linaria and some unknown plant. Even though his living specimens died off, he had seen fully developed seeds inside the flowers. And even though he did not try to grow those seeds, this observation convinced him that they were fertile, could have germinated, and could have grown into young plants similar to the parent plant.
However, his theory was complicated by two unresolved problems. First, he could not determine the other parent plant of the cross. Second, because he did not try to grow any seeds, he was operating on an untested hunch. If its seeds could grow into new, similar plants with five stamens and five spurs, he would be forced to conclude that a new species could originate in nature. Unlike a sterile animal hybrid, a fertile hybrid plant would be a new species.
If Linnaeus had traveled to the island and seen the abundant root structures himself, he would have realized that this plant did not always need seeds to reproduce. With a little digging, he would have traced the stems of these new plants back down into the soil to their source—horizontal rootlike structures coming from the linaria plants. He would have recognized that this growth was similar to ivy and pachysandra—and bananas. This type of underground stem, a rhizome, could send up shoots and send down new roots, invading an area by starting lots of new plants. No seed required.
Since Linnaeus did not travel to the island, he saw no other possible verdict: He was convinced that this was a newly-formed plant produced by the union of two different kinds of plants, and that it could produce young plants like itself. It was, he determined, a new species.
This was an extremely risky hypothesis. The theological implications were disturbing. It challenged the idea that no new species could emerge after the Creation. It derailed his own long-held belief that species could never change. Linnaeus named this new plant peloria, from the Greek word pelor, meaning “monster.”
He wrote that a new species of plant growing from a common linaria would be “strange and unbelievable . . . it would not appear to be a greater miracle than if apple trees were to produce daffodils.” He continued:
Nothing can, however, be more fantastic than that which has occurred, namely that a malformed offspring of a plant [differs from its mother plant and its entire class, making it] an example of something that is unparalleled in botany.
Yet, unless God had formed this species on that island off Stockholm’s coast, Linnaeus admitted that an important mystery remained. “[What causes] the transformation of Linaria into Peloria is to us still unknown.” He used the Latin word mutatae, or “mutates,” by which he simply meant “changes.”
Linnaeus concluded in his dissertation:
If with certainty it could be established that Peloria is a hybrid herb that traces its origin from Linaria and another plant, then, a new truth from this would emerge within the plant kingdom . . . If [common] Linaria does not arise again from Peloria, a fantastic conclusion follows as a consequence, namely that it can occur that new species arise within the plant kingdom . . .
The theory—that a hybrid plant was capable of reproducing—intrigued some people and infuriated others.
“Your Peloria has upset everyone,” warned Johan Browallius. Linnaeus’s friend from Falun was now a natural history professor in Finland and later would become a Lutheran bishop. “[B]e wary of the dangerous sentence that this species had arisen after the Creation,” he wrote. Do not, Browallius stated flat out, reach that conclusion. They were both well aware that only a hundred years earlier the Church of Rome had condemned Galileo’s work in astronomy. History was filled with thinkers who had been persecuted for introducing new ideas.
