Demystifying White Snakeroot

A historically intriguing, yet over-looked fall wildflower is blooming now. It's a plant one-to-four ft. tall found at the edge of yards and open woods, always under some shade, sporting button-like flower heads, up to a half-inch across, crowded with 8 -- 30 individual star-shaped small bright white flowers. Although the plant -- white snakeroot -- is relatively common, it is overlooked given its somewhat weedy habit.

Botanists, who seem to have a problem making up their minds on the "correct" scientific name, deem it Eupatorium rugosum, Ageratina altissima and Ageratum altissimum, among others.

In 19th century America, mostly on the western frontier (today's Midwest) there was a serious, often fatal disease known as "trembles" or "milk sickness." It was first described in an 1809 medical journal, observed in settlers in Tennessee and Kentucky. One curious aspect of the now little-known disease is that after the first frost, the malady was stopped cold.

Symptoms of milk sickness include prostration, severe vomiting, tremors, liver dysfunction, constipation, delirium, and death. The disease affected cows, sheep and other livestock. There was only one way for humans to contract milk sickness -- drinking fresh cow's milk or consuming dairy products, such as butter.

By the late nineteenth century, white snakeroot was suspected as the probable culprit and small farmers were advised to keep their livestock away from the plant. After mystifying researchers for more than 100 years, the cause of the disease was finally solved when in 1928 a USDA researcher isolated an oily alcohol from the fresh plant, deemed tremetol, and confirmed that it caused the disease in animals. Tremetol only occurs in the fresh plant. The compound is destroyed when the plant is heated or dried, which explains why the disease ceased to exist each year after a hard freeze -- the fresh plant was gone.

If two or three cows on a small family farm grazed on the fresh plant in shaded open woods, toxic tremetol was concentrated in their milk. Since the plant did not grow in open pastures on larger dairy farms that supplied milk to urban populations, the disease was virtually unknown in cities. Instead, it affected people isolated to rural farmsteads.

Victims contracted the disease simply by drinking milk. The disease claimed thousands of lives in the nineteenth century. Milk sickness often claimed entire families. The most famous victim was Abraham Lincoln's mother, who died of milk sickness when Lincoln was seven years old.