White wildflower has a dark past
On October 5, 1818, Abraham Lincoln’s mother, Nancy Hanks Lincoln, died from the “milk sickness” a perplexing fatal disease that took the lives of thousands in the Western frontier from sometime in the colonial era into the first two decades of the 20th century. It often affected entire families and destroyed communities. The only way to contract the disease was by drinking milk or eating butter. Cause of the disease confounded science into the 1920s.
By the late 19th century one plant, a wildflower, emerged as a suspect – White Snakeroot. Blooming now, this fall wildflower is a plant one to four feet tall found at the edge of yards and open woods, almost always in dappled shade, sporting button-like flower heads, up to a half-inch across, crowded with eight to 30 individual star-shaped small white flowers. Although the plant is very common, it is easily overlooked given its somewhat weedy appearance. Botanists, deem it Eupatorium rugosum, Ageratina altissima, Ageratum altissimum, among other names. Most current works list it as Ageratina altissima.
Like the plant that causes it, the milk sickness had many names including sick stomach swamp sickness, trembles, slows, puking fever, and river fever. One curious aspect of the now little-known disease is that after the first frost, the malady was over until the next spring. Symptoms of milk sickness include prostration, severe vomiting, tremors, liver dysfunction, constipation, delirium, and death. The disease also affected cows, sheep and other livestock. There was only one way for humans to contract milk sickness –drinking fresh cow’s or goat’s milk or consuming dairy products such as butter. About 25 percent of people who consumed the tainted dairy goods died from the disease.
In 1908, a USDA researcher, A. C. Crawford authored a U.S.D.A Bulletin, “The supposed relationship of white snakeroot to milksickness or trembles.” He had proven that the dried plant produced no symptoms of milk sickness. He missed an important clue. Milk sickness only occurred during the growing season before the first frost of autumn. Crawford failed to realize that only the fresh plant was toxic. He only tested dried plant material and only proved that the dried plant was inert.
In 1926, another USDA chemist, James F. Couch, showed that fresh, not dried, White Snakeroot caused milk sickness. The following year he isolated the chemical complex – tremetol – as the toxic component. The mystery of milk sickness which claimed Abraham Lincoln’s mother and countless thousands of other settlers was finally solved.