The Plant that Killed Mrs. Lincoln

In these last moments of autumn, only a handful of fall wildflowers are still in bloom, mostly goldenrods, asters, and a few of their cousins. And one of those flowers blooming now occupies a curious place in American history-- and a growing place in my affections.

It’s the plant that killed Mrs. Lincoln, Abraham’s mother Nancy, when the future president was only nine. And it likely grows not very far from wherever you live-- it is a vigorous weed that loves my own yard.

It's white snakeroot, another member of the large clan of composite plants, cousin of the aforementioned aster and goldenrod. Snakeroot’s clusters of bright white flowers bloom from early summer deep into the fall, earning it the genus name Ageratina, which translates as “un-aging.” Tolerant of shade, the flower can be found in many habitats, from disturbed roadsides and powerline cuts to forests and thickets, and volunteers in gardens like mine, though few others welcome it as I do.

The plant can grow up to three feet tall (its species name, altissima, translates as “tallest,” as this is the tallest member of the genus) and its coarsely toothed leaves have long tips at their ends. The abundant white flowers are flat-topped and mature into fuzzy white seeds that widely spread through wind dispersal.

Milk Sickness and Mrs. Lincoln

I’ve always assumed the plant’s common name derived from a long snaky root-- which it sort of has. But that’s not it. Instead, as the plant is toxic, it was mistakenly thought that a poultice of its roots could cure snake bites. However, when cows eat the plant, its toxin passes into both meat and milk, and if someone consumes enough, it may cause death. “Milk sickness,” as it was called, was a huge problem across pioneer America. 

Amy Stewart, the gifted writer who published Wicked Plants: The Weed that Killed Lincoln’s Mother and Other Botanical Atrocities, reports that “the disease was so common that the names Milk Sick Ridge, Milk Sick Cove, and Milk Sick Holler are still attached to places in the South where the disease was rampant.” It was also prevalent in the Midwest, where the Lincolns lived.

Milk sickness is characterized by trembling, vomiting, and severe intestinal pain, and if untreated, the symptoms can progress to weakness, difficulty standing or walking, complete loss of muscle coordination, stupor, and even coma; death usually occurs within a few days of the onset of these symptoms. Oddly, adult cows were not affected, but the disease killed their calves, and goats, horses, and sheep all fell victim to the plant’s poison. 

Mrs. Lincoln succumbed after a week’s sickness, and her aunt, uncle, and several people in their town of Little Pigeon Creek, Indiana died then as well. She was only 34 at the time, and young Abraham helped carve the pegs for the wooden casket fashioned by her bereaved spouse. Never close to his father, many historians see Nancy’s death as triggering the depression that seemed to haunt the president.

An Illinois doctor named Anna Hobbs Bixby-- trained in Philadelphia, I might add-- is credited with solving the riddle of milk sickness. Stewart writes Bixby “noticed the seasonality of the disease and speculated that it might have something to do with the emergence of a particular plant in the summer.” She finally confirmed it was snakeroot, and led a campaign to eradicate the disease.

Two footnotes: one, Stewart also writes that “unfortunately, (Bixby’s) attempt to notify authorities fell on deaf ears, perhaps because women doctors were not taken seriously.” Two, Wikipedia’s entry for milk sickness cites a 1967 Minnesota publication that alleges the good doctor befriended an older Shawnee woman who provided the causal link between snakeroot and milk sickness. Of course First Nations people knew the medicinal properties of all the plants in the woods and fields, as the outdoors was their Rite Aid. If this story is true, the elderly woman sadly never received credit for the tip.

While it didn't cure snake bites, Native Americans used it to treat diarrhea and kidney stones, and the leaves were burned to, amazingly, create a smoke that revived unconscious people.

White snakeroot has long been a rather invasive visitor in my small property’s gardens and yard, as it is quite persistent and wants to take over. Only knowing it was native and bloomed late into the fall season kept me from wanting to eradicate it. But now, knowing its place in American history, my affection for it approaches that of the bumble bees, greedily visiting it even today as one of fall’s very last flowers.

Once you know the plant, you’ll be surprised by the number of places you’ll stumble upon it. And maybe you’ll like it as much as me and the bees.