365 Urban Species. #263: White Snakeroot
Photos by cottonmanifesto. Location: The sidewalk in front of my house, Brookline.
Urban species #263: White snakeroot Ageratina altissima (also often listed as Eupatorium rugosum)
Let's get it right out in the open: This plant killed Abe Lincoln's mom. White snakeroot contains a toxin that builds up in the milk of cows and other livestock that eat it. When the milk is consumed by the animal's baby, or by the mother of the Great Emancipator, a poison called trematol can have a deadly effect. In the early 1800's, thousands of human victims in North America died, due to "milk sickness," as it was called.
White snakeroot is native to eastern North America, and in my experience, is not especially common. When, about a decade ago, I first decided to identify all the weeds in my yard in Brighton, it was there; I've seen it only occasionally since, and haven't thought much of it until this past week, when it appeared along the sidewalk in front of my house. Perhaps its relative rarity is due to its preference for alkaline soils--the soil in eastern cities tends to be acid. It is a flower of shady woodland edges, so the edges of hedge-shaded driveways and sidewalks may be similar enough habitat to invite its growth.
The peculiar name comes from related plants, reportedly used by Native Americans to treat rattlesnake bites. White snakeroot itself was used to treat diarrhea and other ailments--slightly toxic plants often lending themselves to medicinal uses.
