White Snakeroot and Boneset, how to tell the difference and why it is so important

White Snakeroot is a prime example of why it is so important to properly identify plants in the wild before foraging or deciding to add them to your landscape.

Though Snakeroot is a very pretty native plant, it has a sad history behind it.

       White Snakeroot (Ageratina rugosum) was at one time known as Eupatorium urticaefolium and similar to Boneset (Eupatorium perfoliatum). Below are two videos with very good information on how to tell the difference between these two plants. Key differences are in the leaf shape and form. Snakeroot has its petioles in a lateral, horizontal formation with flatter, broader, pointed leaves and slightly hairy stems. Boneset also has lateral leaf formation but the leaves are perforated, which means it looks like the stem goes right through the leaf. The leaves are longer, narrower and turn slightly up at the edges and the stems are hairier than on snakeroot.

Boneset is considered a medicinal plant, whereas snakeroot is a toxic plant. The word Eupatorium means "of a noble father", referring to Mithridates Eupator, a blood-thirst ruler 120 to 63 B.C. Also called Mithridates the Great, he was an overly ambitious ruler of the Asia Minor kingdom of Pontus. He discovered that a species of Eupatorium was an antidote to poison and some say he was the world's first immunologist. 

Snakeroot contains a toxic alcohol called tremetol, which causes ketosis and is transmitted through the milk of cows foraging on the plant. Milk sickness, morbeo lacteo, or the "trembles". was a dreaded disease that attacked 19th-century farm families and their livestock in the South and Midwest. Symptoms include nausea, vomiting, stomach pain, intense thirst, coma and then death. 

Nancy Hanks Lincoln, Abraham Lincoln's mother, died of milk sickness in 1818. 

The cause of milk sickness was identified by an Illinois doctor, Anna Pierce, in the 1830's. She learned the identity of the poisonous plant from a Shawnee woman who was a fugitive from the forced relocations of Native Americans. The snakeroot roots were used by the Indians for snake bites but very toxic if consumed. However, the cause of milk sickness wasn't confirmed until 1917.

Dairy cows may still eat white snakeroot on occasion, but since their milk gets mixed with other milk in such huge quantities, the poison has no effect. Though poisonous, being it is a native perennial in zones 3-8, some nurseries offer snakeroot as a plant that does well in partial shade. 

This plant has its benefits in that being it blooms in late September into October, it is a food source for insects when many other plants have already gone to seed. 

A pretty plant, white snakeweed can be left alone wherever it turns up, as long as it isn't consumed. Deer seem to know this plant is toxic so if deer resistant plants are sought after, white snakeroot is an option. Just be careful with pets if they are young and prone to chew on everything.