Among Kalm’s North American treasures was a fast-maturing corn from which, he predicted, “more than one barrel of gold will be gained.” He had squash, wax myrtle for making candles, white cedar for fence posts, and sugar maple for producing syrup. He had hardy mulberry trees that promised a breakthrough in the Swedish production of silk. He had medicinal plants, including ginseng, which the French used as a stomachic, and the great blue lobelia, which the Cherokee used against syphilis.
The report Kalm sent to his university administration catalogued the failures that ensued. His lobelia sprouted, “but it did not have time to gain any strength before the severe winter arrived, wherefore it withered.” His mulberries failed to grow “more than a finger regardless of the care I have given them.” Although his squash plants bore “beautiful and ripe fruit,” the Swedes never developed a taste for them. According to Kalm authority Karen Reeds, only two of Kalm’s North American imports ever achieved popularity in Scandinavia: the cockspur hawthorn and the Virginia creeper.
In the end, Kalm lacked what it took to be one of Linnaeus’s favourites. His personality was too bland, his prose too tedious. Published starting in 1753, Kalm’s three-volume Travels into North America is not exactly a page turner, though rich in botanical and sociological description. While only two of Linnaeus’s letters to Kalm survive, it is noteworthy that Kalm stopped writing to his mentor in 1758, presumably because Linnaeus had lost interest in his career.
Perhaps Kalm’s most important legacy is that of names. He brought Linnaeus specimens of at least ninety North American plants, from the black raspberry to poison ivy. Some sixty were new to science, as yet unnamed. Although the great blue lobelia never did cure syphilis, Linnaeus respected Kalm’s story enough to name the plant Lobelia siphilitica. More than a few times, Linnaeus paid homage to Kalm’s Canadian journey, naming wild ginger Asarum canadense (“of Canada,” in reference to the general northeast region), the Canada violet Viola canadensis, and wild onion Allium canadense.
And Linnaeus ultimately did reward Kalm as only he could. He named an entire New World genus of plants, the beautiful laurels, Kalmia. This gesture was due, Kalm humbly wrote, to “the peculiar friendship and kindness with which he has always honoured me.”
The best way to get to know Linnaeus is by heading out into nature. Had I chosen to retrace his path through Lapland, I would have been in for rotten weather and a lot of reindeer meat. Instead I chose a far gentler trail, biking through Uppsala on a beautiful morning in May.
Uppsala is a very green city, with about 160,000 bicycles, nearly one for every resident, and an impressive system of bike paths. For the jubilee, the city created a blue-flagged Linnaeus Trail leading sixteen kilometres out to Hammarby, Linnaeus’s country estate. Two days before his birthday, I set out on my borrowed bicycle, the quaint, upright Swedish kind. My first stop was a famous field where thousands upon thousands of snake’s head fritillaries were in bloom — maroon ones and white ones, their petals patterned in an exquisite checkerboard. Linnaeus believed the plants, which are not native to Sweden, escaped from a nearby botanical garden.
Along my route, signs in Swedish and English indicated spots where Linnaeus once led his students on natural history walks. From time to time, he also organized mass excursions through the countryside, with up to 2,000 people and musicians from the local military marching band. When someone brought him a worthy specimen, the bugler would sound a fanfare, and everyone would come running to hear Linnaeus’s commentary.
Climbing gradually, one reaches the redbrick Lutheran church that Linnaeus attended on Sundays, accompanied by his dog. A few kilometres farther down the same road is Hammarby, where Linnaeus spent summers with his wife and five children in a charming wooden house that still stands, along with his now empty natural history museum. The Siberian crabapple planted by Linnaeus was in bloom; I laid my hand on its 250-year-old trunk. In the rocky garden grows a patch of dog’s mercury — the plant pictured, along with Linnaeus himself, on the Swedish hundred-kronor note. Linnaeus wrote about dog’s mercury while still a student at Uppsala, in an essay called Praeludia Sponsaliorum Plantarum, “On the Foreplay to the Wedding of Plants.” Dog’s mercury has separate male and female plants, a fact that helped Linnaeus conceive his sexual system for classifying flora.
Linnaeus’s system is no longer used by botanists, because by the early nineteenth century scientists considered his classifications too arbitrary, being based solely on a flower’s sexual organs. The modern system groups plants into families according to similarities in their leaves, stems, and flowers. This system, too, is changing. Genetic sequencing has forced botanists to revisit old assumptions about plant relationships, as species that look similar sometimes turn out to have divergent evolutionary histories.
